Blueberry Coffee Cake Muffins in 40 Min

Instructions:

1. In a medium bowl, whisk together the flour, brown sugar, and cinnamon for the streusel.
2. Add the cold, cubed butter to the streusel mixture. Use a pastry cutter or fork to work the butter in until the mixture resembles coarse sand with some pea-sized lumps. Set aside in the fridge.
3. Preheat oven to 400°F (200°C) and line a standard 12-cup muffin tin with paper liners.
4. In a large bowl, whisk together the flour, granulated sugar, baking powder, and salt until fully combined.
5. In a separate bowl, whisk the sour cream, eggs, melted butter, and vanilla until the mixture is smooth and emulsified.
6. Pour the wet ingredients into the dry ingredients. Using a spatula, fold gently until just combined; the batter should remain thick and slightly lumpy.
7. Toss blueberries in a pinch of flour, then gently fold them into the batter using a spatula.
8. Divide the batter evenly among the muffin liners, top each with a generous portion of the chilled streusel, and bake for 25 minutes.