Chocolate Hazelnut Mousse Cake

INGREDIENTS

1/4 cup

hazelnuts, skins rubbed off - about 34 hazelnuts

2 tbsp

granulated sugar

1/2 cup

unbleached all-purpose flour

1/4 cup

unsalted butter, room temperature

2 tbsp

Dutch-process cocoa powder

salt

1 tsp

unflavored gelatin

3 tbsp

cold water

1/2 cup

Nutella Hazelnut Spread

1/4 tsp

espresso powder

1/2 cup

mascarpone cheese

1 tsp

vanilla extract

1 1/2 cups

heavy whipping cream

2 tbsp

Dutch-process cocoa powder

3 tbsp

granulated sugar

1/3 cup

heavy cream

4 oz

bittersweet chocolate, chopped

1/4 cup

toasted chopped hazelnuts for garnish