I mix in about 1 1/2 to 2 cups then knead in the rest on a lightly floured surface.
Roll the puff pastry onto a floured surface until it is about 1cm thick.
Place the dough on the floured surface and toss in the flour until it is easy to handle.
Pour the brownies into a nine inch by nine inch greased and floured pan.
On a floured surface, let the puff pastry come to room temperature.