Preheat the oven to 350F and line an 8x8 inch pan with parchment paper. Melt 1/2 cup butter and the chopped chocolate together in the microwave in 30 second bursts, stirring until smooth.----------------
Whisk the allulose into the melted chocolate, then whisk in 2 eggs and 1 tsp vanilla for a full minute until glossy. Stir in 1/2 cup almond flour, cocoa powder and 1/4 tsp salt until smooth. Spread the brownie batter evenly into the pan.----------------
For the cookie layer, beat the softened butter with the golden monk fruit sweetener until creamy, then beat in 1 egg and 1 tsp vanilla.----------------
Stir in 1 cup almond flour, coconut flour, baking powder and 1/4 tsp salt until a soft dough forms, then fold in the chocolate chips.----------------
Drop spoonfuls of cookie dough over the brownie batter and gently press them down so the cookie layer covers most of the surface, leaving a few brownie patches peeking through.----------------
Bake for 28 to 32 minutes, until the cookie top is golden and the center is set. Sprinkle with flaky sea salt as soon as it comes out of the oven.----------------
Cool completely in the pan, then refrigerate for 30 minutes for the cleanest slices. Lift out and cut into 16 bars.