For brownie batter
1 stick (1/2 cup) unsalted butter, cut into pieces
4 ounce semi or bittersweet chocolate
3/4 cup sugar
2 eggs -(reserve one yolk for cream cheese batter
2/3 cup WW pastry flour
For cheesecake batter
8 ounces cream cheese, well softened
1/3 cup sugar
the reserved egg yolk
1/4 teaspoon pure vanilla extract
Put oven rack in middle position and preheat [...]