If you're looking for a gluten-free option, this blueberry crumb cake recipe is perfect for you. It's made with almond flour, coconut flour, and tapioca starch, which gives it a light and fluffy texture. The blueberry filling is made with fresh blueberries, lemon juice, and honey, which adds a natural sweetness. To make the cake, mix the dry ingredients, cream the butter and sugar, add the eggs and vanilla, and alternate adding the dry ingredients and milk. Fold in the blueberries and pour the batter into a greased baking dish. For the crumb topping, mix almond flour, coconut sugar, and butter until crumbly, and sprinkle over the cake batter. Bake for 45-50 minutes, and enjoy a delicious gluten-free dessert!