Generously grease a small 6in or 6.5in cast iron skillet with avocado oil or your oil of choice. (I would not use olive oil due to the strong taste.)
Set the pan aside.
Combine the almond flour, coconut flour, baking powder, sea salt, and coconut sugar in a bowl. Using a fork, mix until everything is combined as best you can.
Add in the oil, milk, and lemon zest. Stir it with your fork until a batter forms.
Gently mix in the blueberries.
Pour the batter into your skillet and spread it out evenly so the entire skillet is covered.
Bake it in the oven for 25-30 minutes or until the top is golden brown and knife inserted into the center comes out clean.
Let it cool for 10-15 minutes on a wire rack before cutting into it or removing it from the pan.
*You can also substitute an equal volume of my homemade paleo flour blend.*Small 6in or 6.5in cast iron skilletThe nutrition facts presented here are estimates only. The brands you use and product types chosen can change the nutritional information presented. To obtain the most accurate nutritional information, you should calculate the nutritional information with the actual ingredients you use.