I made these for the first time last year, and they were immediately added to the holiday baking list. I'm not sure that brownies are the right name for them, as the chocolate dough is actually rolled, but once baked with the pistachio filling it turns chewy and brownie-like. I adapted these from a spice biscuit covered almond paste recipe called Gevulde Speculaas in Warm Bread and Honey Cake by Gaitri Pagrach-Chandra. They are completely different tasting, and I find them even moister than the original. I love them without spice, but I think some in the chocolate mixture would make these even more festive.
Making your own pistachio marzipan is a lot of work, but worth it, I think, for the gorgeous colour and flavour. If you can find shelled, blanched pistachios you will save yourself a lot of work. If you can only find them in the shell, pick up about double the weight called for. Make the marzipan first, as it keeps well too. You may as well make a double batch...
These keep very well and improve with age, but don't be surprised if you find yourself cutting a slice every time you walk by, like I did. —MaryMaryCulinary
Combine flour, cocoa, baking powder, salt and sugar in a food processor and pulse to combine.
Add the butter and pulse until it resembles breadcrumbs.
Add the beaten egg and run the processor just until it comes together. Divide dough into 2/3 and 1/3 and flatten into a rectangle. Wrap in plastic and refrigerate for one hour. The dough can be made the day before, but will need to sit at room temperature to soften a bit so it doesn't break up when rolling.
Peel off the top layer of plastic wrap, then flip it over into the pan, Press it onto the sides of the pan so it doesn't collapse, then remove the plastic wrap.
Bring a large pot of water to a boil and blanch the nuts for 30 seconds to one minute. Test by rubbing with your nail to ensure that the reddish skins will come off easily. Drain and rinse with cold water.
One by one, squeeze the pistachios to remove the skin. This will ensure your marzipan is bright green. Once skinned, dry on a towel lined baking sheet for at least 3 hours. Do not dry in the oven as the colour may fade.
Add egg whites and process until well blended. This is the pistachio marzipan, which can be used for any number of delicious things, and keeps well in the fridge or freezer.dessert
Mix the pistachio marzipan with enough of the beaten egg to make a soft, spreadable filling. It will probably take about 1/2 to 3/4 of the egg. Save the rest for glazing the top.