Preheat the oven to 350ºF. Line an 8x8 baking pan with parchment and set aside.
Add the oats, almond flour, starch sugar into a food processor. Process until combined and the oats are a crumbly texture. Add the oil and egg and pulse together until a sticky dough forms.
Pour the dough into the baking pan and press it flat using your hands. Poke a few holes in the dough with a fork to let the steam escape.
Bake the crust for 8 - 10 minutes while you make the filling.
Add all the filling ingredients into a blender. Blend on high until smooth.
Once the crust has finished baking, pour the filling on top. Carefully transfer it back to the oven and bake for another 16- 18 minutes.
Remove the bars from the oven and allow them to cool at room temperature for at least 30 minutes, then transfer to the fridge and cool completely.
Cut the bars into squares and sprinkle with powdered sugar.