Separate 3 of the eggs. set aside the 3 egg whites. Mix the 3 whole eggs and 3 yolks with the sugar and butter and beat well. Next add the milk and pistachio butter and mix well. In a separate bowl, mix the dry ingredients. In a cold bowl, beat the egg whites to stiff peaks. slowly mix the dry ingredients with the wet ingredients until well combined. Finally fold in the whipped egg whites to lighten the mixture. Do this in 3 batches, each time folding gently until you see no more streaks of white.
In a non stick pan with some butter on medium, pour in a quarter of your batter. Give it about 5 minutes on the stovetop, then put it in a 500 degree oven for about 5-10 minutes until the top looks fully cooked. Put it back onto the stovetop and finish cooking before flipping it out onto a cooling rack.
Frost with a nice dark chocolate buttercream. I have no idea what was in mine, I started with one from a very popular food blog and this is the third recipe I have been not happy with from it! The buttercream broke and I tried heating it to save it but it wouldn't come together. Then I started running around my house trying to get any natural emulsifier into the frosting. Finally i pulled it together with a sprinkle of gelatin, some melted chocolate, and an aggressive mixing with a stick blender.