2/3cupPowdered erythritol(adjust to taste; regular granulated *not* recommended)
Preheat the oven to 350 degrees F. Line the bottom of a 9" round springform pan with parchment paper.
In a large bowl, beat together the erythritol and butter, until fluffy.
Beat in the eggs, one at a time, then the almond milk and vanilla extract.
Beat in the almond flour, coconut flour, and gluten-free baking powder.
Transfer 1/3 of the dough to the lined pan and smooth the top with a spatula. Bake for 18-22 minutes, until the top is lightly golden and spring-y. Repeat with another 1/3 of the dough, then again with the final 1/3 (making 3 layers total).
Meanwhile, make the frosting. Beat together the cream cheese, butter, powdered erythritol, and vanilla extract, until smooth.
Let the cake layers cool separately to room temperature before stacking. Frost between the layers, and all over the top and sides at the end. Top with chopped pecans (optional) if desired.