Mix dry ingredients: In a medium bowl, combine almond flour, 2 tbsp coconut flour, and ¼ cup sweetener.
Cut butter into dough: Using a pastry blender or your fingers, work the cold butter into the dry mixture until it forms coarse crumbs.
Press into pan: Evenly press the mixture into a 9″ pie plate, gently shaping up the edges.
Prebake the crust: Place the crust in the oven and bake at 350°F for 10 minutes. Remove and let cool.
Activate gelatin: In a small bowl, sprinkle 2 tsp gelatin over 2 tbsp cold water. Let sit for 5 minutes.
Heat sweetener mixture: In a microwave-safe bowl, combine remaining 2 tbsp sweetener, 3 tbsp water, and vanilla extract. Microwave for 30 seconds to dissolve.
Combine with gelatin: Add activated gelatin to the warm sweetener mixture and stir vigorously with a fork until fully incorporated.
Spoon into crust: Carefully pour the warm filling into the prebaked crust and smooth the surface.
Melt coatings: In a small microwave-safe bowl, combine hazelnut spread and chopped dark chocolate. Microwave in 30-second increments until glossy and melted.
Drizzle over pie: Drizzle melted coating over the filling. Let set in the refrigerator for at least 1 hour before slicing.