This gluten-free blueberry crumb cake recipe is perfect for those who are gluten intolerant or have celiac disease. The cake is made with almond flour and coconut flour, which gives it a nutty and slightly sweet flavor. The blueberry filling is made with fresh or frozen blueberries, lemon juice, and honey, which gives it a tangy and sweet taste. The crumb topping is made with gluten-free oats, almond flour, and coconut sugar, which gives it a crunchy texture. This recipe is easy to make and can be served warm or cold, with a dollop of coconut whipped cream or a scoop of dairy-free ice cream.