Preheat the oven to 350°F. Grease the wells of a standard muffin pan or line with baking cups. Set aside. , In a large bowl, whisk together the flours, sugar, baking powder, salt, and cinnamon.  , In a medium bowl or large measuring cup, whisk together the milk, eggs, vegetable oil, and vanilla until well combined. , Pour the liquid ingredients into the dry ingredients. Using a flexible spatula, stir to combine.  , Fold in the blueberries until just combined. , Spoon about 1/4 cup (roughly 67g) of the batter into each prepared muffin well, filling them nearly full. A leveled muffin scoop of batter is the right amount. , In a small bowl, stir together the topping ingredients. Sprinkle the topping evenly over the muffins. , Bake for 23 to 25 minutes, or until a toothpick or thin knife inserted into the middle of one of the center muffins comes out clean and the muffin tops are lightly golden. , Remove the oat muffins from the oven, and after 5 minutes (or when they're cool enough to handle), transfer them to a rack to cool slightly. Serve warm, or at room temperature.  , Store leftovers in an airtight container at room temperature for 2 to 3 days; freeze for longer storage.