Preheat your oven to 325°F.
Take out an 8x8 inch baking dish and line it with parchment paper, leaving a 2–3" overhang on the sides for easy lifting.
Take out a large bowl to prepare your crust.
Add all of your dry ingredients for the crust and mix them together.
Add your wet ingredients for the crust into the bowl with the dry ingredients and mix everything together until it resembles wet sand.
Press your mixture evenly into the bottom of the pan using a spatula or measuring cup.
Bake on 325°F for 12–15 minutes until lightly golden.
Remove and let cool for 5 minutes.
Take out another large bowl to prepare your filling.
Add all of the dry ingredients for the filling and mix them together.
Add your wet ingredients for the filling into the bowl with the dry ingredients and mix everything together until it's completely smooth.
Pour your filling over the pre-baked crust and return to the oven.
Bake on 325°F for 35–40 minutes, until the edges are set but the center has a slight jiggle.
Let them cool at room temperature for 15 minutes, then refrigerate for at least 2 hours.
However, it's highly recommended to refrigerate overnight.
Take out your dish and use the parchment overhang to lift the bars out.
Cut them into 9 even squares and serve.
Dust with a little powdered sugar or powdered sweetener if desired.