• Oven 160 C / 370-F. You'll need a flat lined baking tray.
• Put the chopped butter and chocolate into a bowl and melt together. Set aside
• Put the eggs and sugar and vanilla into the bowl of a mixer with the paddle attachment and beat on high until the mixture is light and airy. About 5 minutes.
• Meanwhile combine the flour, baking powder and cocoa in a bowl and whisk to combine the ingredients
• Pour the just warm chocolate and butter mixture into the egg mixture and beat together to combine well. Stop the mixer and add the flour mixture and mix on low till well combined.
• Put even sized spoonfuls onto the tray well spaced apart. Gently push them intro uniform shapes with the back of a spoon. Flattening them a bit to form a cookie. You will be pairing these cookies off so try and keep them a uniform size.
• Bake the cookies for 12-15 minutes. They will be done when they are not soft and sticky on top.
• Let them cool for just a couple of minutes before removing onto a cooling rack with a palette knife or egg turner. Continue with more mixture. ( should make 24-28 singles)

To make the filling

• Put the cream into a jug and heat till quite warm but NOT boiling. Add the chopped white chocolate and stir to dissolve all the lumps. Refrigerate until it is just starting to set.
• Match all of the brownies with partners about the same size, then put a nice big spoon of white chocolate on 1 half of each pair. (the chocolate should not be runny, it should be molten but thick and easy to work with). Sandwich them together.
• The Brookies will keep very well in a cool place in an airtight container.