Set the butter in a large, light colored frying pan. Cook on medium as it melts then begins to separate; you’ll see cream colored bits dropping to the bottom of the pan. Keep cooking, stirring frequently, until the bits turn a toasty brown color. Transfer to a large bowl and let cool completely. If your kitchen is cold, leaving it on the counter will get it to a solid state but if not, let it sit in the fridge until it’s the consistency of softened butter.

Preheat the oven to 350 F. Line a 9x9 inch square metal pan with parchment paper (two overlaying sheets so all sides are covered).

In the bowl of a stand mixer, add the sugar and softened brown butter. Affix the paddle attachment and beat until light and airy - the mix will turn several shades lighter and it will take at least 5 minutes. Add the salt and vanilla as it beats.

Add the eggs, one at a time, beating well after each addition. The mixture will turn shiny as the eggs are incorporated.

Sift in the cake flour and add the baking powder and start beating to incorporate. When it’s halfway mixed, add the sour cream and beat until smooth.

Pour the batter into the prepared baking pan. Gently shimmy the pan on the counter so the batter is even.

Bake the cake until a cake tester comes out clean - about 40 minutes (different ovens/pan materials can lead to different bake times, always go by visual cues and not a listed time which is there only as a guide).

Let the cake cool in the pan for about 10 minutes then transfer it to a cooling rack until it’s cool enough to touch. Slice off the cake hat (where it has risen in the middle) so that the layers will be even (enjoy it as a snack!). Now slice the cake in half horizontally, a cake slicer is best here but a bread knife and a steady hand can work too) so you have two flat 9 inch cakes. Slice down the middle of the cake (around the 4-4.5 inch mark) to cut it vertically so you have four small rectangles. Let these cool completely before assembling the cake.

Slice a quart of strawberries thinly. If your berries aren’t particularly juicy and flavorful, add a teaspoon of sugar, a pinch of salt and a bit of lemon juice and let them soak for 10-15 minutes - remove the excess liquid before adding these to the cake.

Prepare the stabilized whipped cream according to the recipe above (all ingredients in the food processor, process until thickened).

Assemble the cake: lay the first cake slice (it should be from the bottom of the cake, save the other bottom for the top - the two upper layers can go in the middle), on your serving platter so the interior of the cake is face up. Spread whipped cream over the cake so you have a layer that’s about a centimeter thick, arrange a layer of strawberries on top in a single layer that covers most of the whipped cream. Lay a second cake slice over the berries (this one can be interior face down) and repeat the whipped cream and strawberries layers. Add the third layer and repeat. For the last cake slice, it should be a bottom cake slice and layer it so the interior of the cake is face down. Layer on the last of the whipped cream and strawberries. If you plan to serve this later, consider spreading whipped cream on the sides to protect the cake from drying out.

To serve: slice the cake from the shorter end of the rectangle. Leftovers don’t keep very well as the berries will release more juices and make the cake/cream soggy so enjoy it the day of!