Preheat oven to 375 degrees F. Line a muffin pan with paper liners or grease well.
In a small bowl, make the flax egg by combining the ground flaxseed and water. Set aside for 5 minutes to thicken.
In a medium bowl, add the milk and lemon juice (make sure you zest the lemons before juicing it). Stir and set aside.
In a large bowl, add the oat flour, almond flour, baking powder, baking soda, and salt. Whisk until well combined.
In the bowl with the almond milk/lemon mixture, add the applesauce, coconut sugar, maple syrup, vanilla, tahini, lemon zest, and flax egg. Whisk until well combined.
Add the wet to the dry. Stir with a spatula until just combined. Fold in 3/4 of the blueberries. (If blueberries are frozen, toss them in some arrowroot or cornstarch before adding them into the batter.)
Fill each muffin tin to the top (you want big muffins) and top with leftover blueberries. Bake in the oven for 23-28 minutes, or until a toothpick inserted in the middle comes out clean. Let it cool in the pan for 10 minutes, then remove and place on a wire rack to cool completely! Enjoy!
Store leftovers in an airtight container on the counter for up to 3 days. TBH, it tastes even better the next day as the flavors have more time to develop, but it’s still delicious day of!