Gather all ingredients and prep them. Pre-heat oven to 350F. Line a square baking dish with parchment paper and set aside.

For the cake, beat together the butter and sweetener in a bowl until light in color and slightly fluffy.

Add in the eggs, heavy cream, and vanilla extract and beat to incorporate.

Add in the almond flour, baking powder, and salt and beat again until smooth.

Transfer the batter to the square baking dish and use a spatula to smooth out the top. Bake for 20-25 minutes until golden brown or an inserted toothpick comes out clean.

While the cake is cooking, start on the filling. Beat the egg yolks and powdered sweetener in a metal bowl, then place over a pan to create a double-boiler.

Turn the pan on to boil the water and once boiling, reduce heat to low. Cook the egg yolk mixture for 4-5 minutes while continuously stirring until the mixture is lighter in color and slightly frothy.

Take the mixture off of the heat and beat the mixture again until thicker, darker in color, and smooth.

In a separate bowl, beat the heavy cream until whipped with stiff peaks.

Add the cream cheese and sour cream to the beaten egg yolk mixture, then beat slowly to combine.

Gently fold the cream cheese mixture into the whipped cream.

Once the cake is cooled, remove from the baking dish and put onto a cutting board.

Pour espresso (or strong coffee) slowly over the top of the cake until evenly distributed.

Slice the cake in half, forming 2 large rectangles.

Ice one half of the cake with the filling mixture, then place the second piece of the cake on top of that and ice again.

Dust with cocoa powder and slice to serve. Enjoy as a decadent dessert or rich breakfast!