This blueberry streusel coffee cake recipe is perfect for breakfast or brunch. The cake is made with flour, sugar, baking powder, salt, butter, eggs, milk, vanilla extract, and fresh blueberries. The streusel topping adds a delicious crunch to every bite. 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 streusel topping, mix flour, sugar, cinnamon, and butter until crumbly, and sprinkle over the cake batter. Bake for 45-50 minutes, and enjoy a delicious blueberry streusel coffee cake!