This paleo blueberry crumb cake recipe is perfect for those who follow a paleo diet. The cake is made with almond flour and coconut flour, which are paleo-friendly flours. The blueberries add a burst of sweetness and color to the cake. The crumb topping is made with almond flour and coconut sugar, making it crunchy and delicious. Serve it with a cup of black coffee or tea for a perfect paleo dessert.