Brownies:
Melt butter and chocolate together. Set aside to cool.
In
a small bowl mix flour, baking powder and salt together.
In
a large mixing bowl, beat the eggs and sugar together
until light. Add the vanilla. Stir in the flour mixture,
and the cooled chocolate mixture.
Pour
into a greased 8 inch square pan.
Topping:
Beat all ingredients together until smooth.
Drop
spoonfuls of peanut butter mixture over the brownie
layer. Run a knife through the cake to marble.
Bake
at 350 degrees F. for 25 to 30 minutes. Cool, and cut
in squares.