Ricotta Brownies

1 cup whole milk ricotta cheese
1 cup butter
4 squares unsweetened chocolate
2 1/2 cups granulated sugar
1 cup chopped nuts
1 cup flour
1/2 teaspoon salt
2 teaspoons vanilla extract
4 eggs

Heat oven to 350 degrees F. Grease a 13 x 9-inch baking pan.

In a heavy saucepan, melt butter and chocolate. With wire whisk, beat in 2 cups of the sugar and 3 of the eggs until blended. Stir in flour, salt, 1 teaspoon of the vanilla extract and nuts. Spread into prepared pan.

Beat ricotta cheese, remaining 1/2 cup sugar, remaining 1 teaspoon vanilla extract and remaining egg until smooth, about 3 minutes. Drop by spoonsful on top of chocolate mixture. Swirl with knife to marbleize. Bake for 40 to 45 minutes.