8 oz cream cheese, softened
1 1/3 cups sugar
3 eggs, at room temperature
2 egg yolks, at room temperature
1 tbs + 1 tsp vanilla extract
¾ cup butter
8 oz semisweet chocolate, chopped
2 tbs dark brown sugar
2 tbs cocoa powder
¾ cup all-purpose flour
Butter and flour a 9 by 9-inch square baking dish and line on the bottom with silicone baking paper.
In a deep mixing bowl with an electric mixer, beat together cream cheese and 1/3 cup of the sugar until smooth, about three minutes. Beat in 1 egg and 1 tsp vanilla until well combined. Set aside.
Bring a medium pot, filled 1/3 with water to a simmer. In a glass bowl that fits over the pot, place butter and chocolate. Stir until about ¾ of the chocolate is melted, then remove from heat and continue stirring until completely melted. Transfer to a large mixing bowl and let cool a few minutes.
Beat sugar and brown sugar into chocolate until smooth and glossy. Beat in remaining 2 eggs and 2 yolks and tbs vanilla. Sift in flour and cocoa and fold into chocolate mixture.
Spread ¾ of brownie mixture into prepared pan. Spread cream cheese mixture over top, being careful not to disturb the brownie batter. Dot on top with remaining brownie batter. With a sharp paring knife, draw blade through layers, creating a swirl pattern (don’t touch bottom of pan with knife or lift while swirling). Bake in a 350 degree oven for about 35 minutes, or until a cake tester inserted in center comes out clean. Cool on a rack for at least 30 minutes (an hour would be better). Cut into 2 ½-inch squares while still in pan and serve. These brownies are fudgy and unbelievably rich, and even improve after being refrigerated for a few hours.