Chocolate Peanut Butter Bars
Adapted from Nigella Lawson
Makes 1 brownie pan full of bars {quantity depends on what size you cut them}

1/2 cup dark brown sugar {packed}
2 2/3 cups confectioners' sugar
1/2 cup + 2 tablespoons softened butter {divided}
1 3/4 cups creamy peanut butter
10 ounces milk chocolate chips
8 ounces bittersweet chocolate {chopped}

Cut a piece of parchment paper big enough to line a standard sized brownie pan, with a bit of overhang. Grease the brownie pan & lay in the parchment paper.

Combine the brown sugar, confectioners' sugar, 1/2 cup butter & peanut butter in the bowl of an electric mixer fitted with a paddle attachment. Blend until smooth. Dump the mixture out into the pan & press it down, making it an even as possible.

Melt the chocolates & 2 tablespoons of butter in a double boiler, or in a heat-proof bowl set over simmering water. Stir occasionally to combine. Spread the melted chocolate over the peanut butter base & smooth out the surface.

Put the pan in the refrigerator, until the chocolate is set. Remove the bars from the pan by lifting on the overhang of parchment paper & slice into squares using a sharp knife. It may help to warm the knife under hot water to get through the hard chocolate layer more easily. The bars are very rich, so 1" squares would be a good size.