Filling:

4 oz. softened cream cheese

1/4 C. sugar

1 egg

2 t. lemon juice

1/2 t. vanilla extract

1/4 C. finely ground roasted hazelnuts (see note)

Brownies:

1 C. semisweet chocolate morsels

4 T. butter

3/4 C. flour

2 T. unsweetened cocoa

1/2 t. baking powder

1/4 t. salt

3/4 C. sugar

2 eggs

1 t. vanilla extract

1/2 C. coarsely chopped roasted hazelnuts (see note)

For the filling: Combine cream cheese and sugar in a mixing bowl and beat with an electric mixer until smooth. Add egg, lemon juice and vanilla; continue beating until well mixed. Use a spatula to fold in hazelnuts. Cover and refrigerate.

For the brownies: Melt chocolate morsels and butter in a double boiler above simmering water over medium heat. Remove from heat and set aside.
 
Sift together flour, cocoa, baking powder and salt in a bowl and set aside.

Preheat oven to 350° F. Combine sugar, eggs and vanilla in a large mixing bowl and beat with an electric mixer until smooth and lemon-colored, about 2 minutes. Beat in melted chocolate mixture, then add flour mixture and continue beating until mixture is smooth. Fold in hazelnuts with a spatula.

Spread half the batter into an 8-inch square baking pan. Spread filling over chocolate, then gently spread remaining batter over filling. Pull a spatula through layers to create a marbleized effect. Bake for about 40 minutes. Allow to cool before cutting into 2-inch squares.

Note: To roast hazelnuts, put shelled nuts in a 275°F. oven for 25 minutes, then rub them with a rough cloth to remove their skins.