Preheat the oven to 350ºF and regulate the rack to the center place.
Place the almond flour, coconut flour, gelatin, sugar and arrowroot flour within the bowl of a meals processor and pulse 4-5 occasions to include. Add the butter and pulse for eight 1-second pulses, or till the combination resembles moist sand. Course of once more till the combination types a agency dough.
Place the dough in a buttered 8×8-inch baking dish and press evenly to cowl the underside of the dish. Bake for quarter-hour or till crust is golden brown across the edges. Let cool when you make the lemon and cranberry layers.
For the blueberry layer:
Place the cranberries and sugar in a medium saucepan and warmth over medium warmth. Stir sometimes and cook dinner till the berries burst and the combination has the feel of jam, about quarter-hour. Add the lemon zest. Pour right into a blender and mix till easy. Pour over the baked base and unfold evenly.
For the lemon layer:
Place the melted butter, honey, eggs, yolks, lemon zest, simply and salt within the high of a double boiler (or place a heatproof glass bowl over a small pot of boiling water). Whisk constantly till combination thickens, like pudding, about 6 minutes. Instantly pour the lemon combination evenly over the blueberry layer to create 2 distinct layers.
Bake for 23 minutes or till filling units round edges. It would nonetheless transfer just a little within the center while you shake it, however don’t fret: the filling will agency up because it cools. Let cool to room temperature after which refrigerate till chilly. Sprinkle with powdered sugar, minimize into bars and serve.
