Prep. Preheat the oven to 400˚F. Lightly grease a 9-inch springform pan with cooking spray and set aside. Toss 1 cup of blueberries with 1 tablespoon of flour and set aside.
Mix the dry ingredients. In a medium mixing bowl, whisk together the flour, sugar, baking powder, and salt; set aside.
Whisk the wet ingredients. In a large mixing bowl, combine the egg, almond milk, yogurt, and vegetable oil and whisk until thoroughly incorporated.
Combine. Using a spoon, stir the flour mixture into the egg mixture; stir just until combined.
Add the blueberries. Gently fold the blueberries into the prepared cake batter, trying not to break up the fruit.
Bake. Pour the batter into the prepared cake pan. Top with remaining blueberries and walnuts. Sprinkle the top of the cake with turbinado sugar and cinnamon. Bake for 22 to 25 minutes, or until a toothpick inserted in the center of the cake comes out clean.
Let it cool. Remove the blueberry coffee cake from the oven and transfer it to a wire rack; let it stand in the cake pan for 10 minutes. Remove the sides of the springform pan and let the cake cool completely before cutting and serving.