Filed under: Chocolate Pies
April 19, 2023

Chocolate Hazelnut Tart

A dream for chocolate hazelnut lovers! Ground up hazelnuts and oreo crumbs make up the crust, the filling is a smooth milk chocolate ganache studded with bits of chopped hazelnut. The tart is topped with a super creamy hazelnut mousse made with cream cheese and homemade hazelnut paste. 

5 from 1 vote
Yield: 1 ten inch tart
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The hazelnut and milk chocolate pairing is always expectedly wonderful, but this tart allows you to experience it in a variety of textures: crunch in the oreo and nutty crust, a softer ferrero rocher like ganache center, and the top – smooth hazelnut bliss, made even more flavorful with the tang of cream cheese. It’s not a lot of work (there’s more chilling and resting than anything) and once done you have quite a fancy, pâtisserie level dish. 


Recipe Ingredients 

Raw Hazelnuts 


I prefer blanched for this, since we’ll be making hazelnut butter for the mousse but if you don’t mind some flecks of darker brown in your mousse it won’t make too much of a difference. 

You will want to toast them yourself, this brings out the flavor so you’ll have freshly toasted very flavorful and crunchy nuts. 


Choosing the right chocolate for the hazelnut tart

For the ganache I prefer a mix of milk and dark chocolates. Since milk chocolates tend to vary in how much milk and sugar is added it can make it a little difficult to know exactly how much heavy cream to get the right ganache consistency. 

Milk chocolates that are low in cocoa solids (like the ‘extra creamy’ varieties) will need less heavy cream or they’ll be overly loose and soft. If you’re able, get a milk chocolate that tells you the percentage of cocoa solids. For the recipe below I’d say use something that’s around 45-50% cocoa solids. 

If you wish to make this layer quite sweet and predominantly milk chocolate I’d reduce the amount of heavy cream added to be  50% of the total of chocolate (so if you use 350g milk chocolate, use 175g of heavy cream). 

If you have a higher tolerance for darker and don’t mind the loss of sweetness, you might appreciate using all dark chocolate, in this case I’d match the heavy cream to the weight of chocolate: 350g each (you’ll have a thicker layer of ganache in this case so you could reduce both the chocolate and heavy cream 250g each to avoid that). 


Chocolate Sandwich Cookies 

Aka oreos, we’re using a sandwich cookie because the included filling is balanced against how much butter we’re adding. So if you want to use a cookie that doesn’t have a sandwich filling, you’ll need to add more butter to get the ‘wet sand that clumps together’ consistency. 

Cream Cheese

A full fat cream cheese gives better consistency because so it’s quite firm(low fat cream cheeses have more water). 


Heavy Cream 

Or heavy whipping cream (they are interchangeable). If you aimed to make this a dairy free tart with dairy free chocolate and df cream cheese you can swap the heavy cream for coconut cream. It should be cold when adding it to the mouse so it can whip up thick, so stick the can in the fridge a few hours before beginning. 


Hazelnut Butter for the Hazelnut Mousse

Hazelnuts toasted then processed until they release their oils and turn into a liquid paste – like peanut butter. 

We’re going to make our own hazelnut butter for the mousse and all we need is a cookie sheet to toast the nuts for about 10 minutes at 350 F, and a food processor to process the nuts. 

It can take up to 10 minutes to coax all of the nuts to turn into ‘butter’ or a thin, soupy texture. Scrape down the food processor and press the nuts into the bottom near the blades every now and then to keep it working. 

At some point it will turn into a thick glob that’s part paste part bits of nuts, keep processing on high and scraping and pressing down as needed. Stop when it’s running off the spoon. 

You can store it in the fridge, it’ll keep for a few weeks. 


Make ahead & how to store this chocolate hazelnut tart 

Once the ganache is in the shell the tart will keep for quite awhile in the fridge (or even freezer in an airtight container). 

The mousse however can tend to separate or seep if left too long so it’s best to make that part the day of serving. 


Tips for a perfect ganache & how to fix broken ganache 


Chop chocolate finely: Dark chocolate especially takes time to melt (it has less milk or cream in it) so to avoid the heavy cream cooling before it can fully melt the chocolate, chop it very finely (no bigger than a black bean). The milk chocolate can be in slightly bigger bits as it will melt quicker. 


Heat heavy cream:  It should be bubbling on the sides and steaming slightly in the center. If you don’t heat it enough it will cool before it can fully melt the chocolate. If you overheat it (like it’s boiling or steaming quite a bit) it will burn the chocolate. 


Let sit, stir well: Once you’ve poured the cream over the chocolate give it a quick stir then let it be for a minute. This will encourage the chocolate to begin melting. Then stir, stir, stir to complete the melting, until you have a smooth, shiny ganache. 


Fixing a broken ganache: Ganache is broken when the chocolate has melted fully but it looks greasy and separated. If it isn’t too far gone you can sometimes ‘rescue’ it by adding more heavy cream and stirring it in to bring it back together. 


Chocolate Hazelnut Tart Recipe

Chocolate Hazelnut Tart

A chocolate ganache tart housed in an oreo crust, both ganache and crust have bits of hazelnut. The tart is covered in a creamy hazelnut mousse.
Prep Time: 30 minutes
Cook Time: 10 minutes
Chill Time: 4 hours
Yields: 1 ten inch tart
5 from 1 vote



  • 320 g or 24 chocolate sandwich cookies
  • 130 g or 1 cup hazelnuts
  • 80 g or 6 tablespoons butter
  • 2 tablespoons powdered sugar

Chocolate Hazelnut Ganache

  • 100 g dark chocolate
  • 250 g milk chocolate
  • 225 g heavy cream
  • 1/2 cup chopped hazelnuts

Hazelnut Mousse

  • 2 cups blanched hazelnuts no skin
  • 112 g cream cheese softened (half an 8 oz package)
  • 120 g or ½ cup hazelnut butter from above
  • Pinch salt splash of vanilla
  • ¼ cup brown sugar
  • 1 cup heavy cream


Make the crust

  • Preheat the oven to 350 F. Process the cookies and nuts until they are finely ground. Mix with the melted butter and sugar until the mixture is like wet sand (it should hold together when you grab some, but not leave an over oily residue).
  • Press the wet crumbs into the bottom and up the sides of a 10” tart pan. Use a measuring cup or bottom of a glass to pack it in tightly.
  • Now lay a sheet of parchment over it and add a smaller cake pan (if you have it, this step isn’t hugely necessary but sometimes it helps keep it all packed in tight). Bake the crust for about 12 minutes. Take it out and let it cool fully.

Make the ganache

  • Add the hazelnuts to a food processor and pulse until chopped finely. It’s fine if it’s uneven and there are bigger and smaller bits.
  • Bear in mind this is a slightly thin layer of ganache (especially in a 10 inch pan) so increase it by 50% if you want a thick layer.
  • Chop all of the chocolate very very finely. If you have some bigger bits of chocolate they should be milk chocolate, it’ll melt faster so it’s not as big of an issue. The dark chocolate bits should be no bigger than the size of a black bean. Add it all to a heatproof bowl.
  • Warm the heavy cream in a pot until it bubbles at the sides and is hot to touch. Pour it over the chocolate and give it a quick stir then leave it for a full minute to begin melting.
  • Stir until it’s smooth, then add the nuts and stir. Pour the ganache into the cooled shell.
  • The tart will now keep for a full week in the fridge.

Make the hazelnut butter

  • To make the hazelnut butter: toast the nuts on a rimmed baking sheet for 10 minutes at 350 F. While still warm, set them in a food processor and process on high until soupy: this will take 10-15 minutes, stopping and starting the machine to scrape down the bowl. The nuts will turn into tiny bits at first, then chunky, then smooth, and as you keep processing it will turn into a runny paste. Let the paste cool before using to make the mousse.

Make the Mousse (make this the day of serving)

  • In a bowl press down on the cream cheese with a rubber spatula or the back of a wooden spoon to remove any lumps. Add the sugar, salt vanilla and beat. Add the hazelnut butter and beat until combined.
  • Pour in the heavy cream and beat (if you are using a stand mixer you can switch to the whisk attachment) until the mixture is light and fluffy, a couple of minutes at most. If it gets grainy and you see the heavy cream separating, add a bit more heavy cream then briefly beating to bring it back together.
  • Store the tart in the fridge, it’ll keep for 3-4 days once the mousse is on.


Tools: 10” round tart pan

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Recipe Reviews

  1. For the hazelnut mousse, am I reading the ingredients correctly that 2 cups blanched hazelnuts makes the 120g butter? This is then combined with the remaining ingredients to make the mousse? Thanks!

  2. I am so excited to make this! When it calls for 24 chocolate sandwich cookies, is that 24 sets of cookies, minus the “cream” filling? Or 24 individual cookies from separated sandwiches?