Combine flour, oats, both sugars, baking soda, baking powder, and salt in a mixing bowl and stir until combined.
Cut butter into mixture until it resembles coarse crumbs.
Stir in egg and cookie butter. Mixture will still be somewhat crumbly.
Press half of mixture into a greased 8″ square pan, and bake at 350 degrees for 15 minutes.
While crust is baking, combine all filling ingredients.
Pour filling onto hot crust, and crumble remaining crust mixture over top.
Bake an additional 20-25 minutes or until top is lightly browned.
Cool to room temperature, then refrigerate at least 30 minutes before cutting and serving. Store leftovers in the refrigerator.
Recipe Notes
Use any citrus you like instead of lime. If using orange, add a tablespoon of lemon juice to increase the acidity and help the filling set.
Use any cookie butter you would like.
If you don’t have cookie butter, use a neutral nut or seed butter instead. Consider adding a 1/4 to 1/2 teaspoon of cinnamon to help replicate the graham cracker taste.
If you like a gingersnap crust on your key lime pie, add 1/4 to 1/2 teaspoon of ground ginger to the crust mixture.
Add a few drops of food coloring to the filling if you’d like.
Add up to 1/2 cup of finely chopped nuts to the crust, or sprinkle 1/4 cup on top.
