Preheat oven to 350 degrees. Line an 8 x 8 inch cake pan with parchment paper. Allow paper to hang over the sides for easy removal. Set aside. Sift the dry ingredients into a large mixing bowl until combined and no lumps in the dry ingredients.
Stir in the eggs, Greek yogurt, both extracts and the keto milk until a thick batter forms. The batter should be thick but still able to pour out of bowl. If too thick add 1 to 2 TBS of room temperature water. (I added 1 TBS of water) Pour the batter into the prepared cake pan and spread evenly.
If using add-ins, scatter the add-ins over the top of the batter. Use the bake of a spoon and tap the add-ins down into the batter. Place in preheated oven. Bake at 350 degrees for 30 to 35 minutes until golden and a tester comes out clean. remove from the oven. Immediately scatter the chips evenly over the top of the cake.
Allow the chips to sit on hot cake for 5 minutes or until they begin to melt. Use a butter knife and gently spread the melted chips evenly over the top of the cake. Allow cake to cool in the pan 1 hour. Grasp the overhanging parchment paper and gently transfer the cake to a wire rack.
Allow the cake to cool completely before slicing into small squares.