In a mixing bowl, combine brown butter, granulated sugar, and brown sugar. Whisk in eggs one at a time, followed by vanilla extract. Mix in flour, cocoa powder, and salt until just combined.

Bake

Pour the batter into a greased baking pan and bake for 25-30 minutes. Allow to cool completely.

Praline Mousse

Prepare the Gelatin

Soak gelatin in water for 5 minutes. Heat until dissolved.

Make Praline

In a saucepan, melt sugar until caramelized. Stir in chopped hazelnuts and pour onto a baking sheet to cool. Once cooled, chop finely.

Whip Cream

Whip heavy cream until soft peaks form. Fold in praline and dissolved gelatin gently.

Vanilla Mascarpone Cream

Whip the Cream

In a bowl, beat mascarpone, heavy cream, vanilla extract, and powdered sugar until smooth and fluffy.

Chocolate Sauce

Make Sauce

In a small saucepan, heat heavy cream until just simmering. Remove from heat, add dark chocolate, and stir until melted and smooth.

Coffee Fluid Gel

Prepare Coffee Gel

Soak gelatin in water for 5 minutes. Heat coffee and dissolve gelatin in it. Pour into a mold and refrigerate until set.

Hazelnut Coffee Crunch

Make Crunch

In a pan over medium heat, combine hazelnuts, sugar, and coffee granules until caramelized. Spread onto a baking sheet to cool and break into pieces.