Step 1

Adjust oven middle position and preheat to 350 F. Line mini muffin tins with muffin liners or grease with cooking spray.

Step 2

Combine flour, brown sugar, butter, and cinnamon in a small bowl. Use your fingers to crumble together until the mixture resembles wet sand. Set aside.

Step 3

In a medium bowl, combine the flour, baking powder, baking soda, and salt and whisk until combined.

Step 4

In a separate bowl mix together butter, oil, and sugar with an electric mixer until evenly incorporated. Add eggs one at a time, beating in between additions until mixture is smooth and all ingredients are incorporated. Add greek yogurt and mix until just combined.

Step 5

Gently mix wet ingredients into dry ingredients until mixture forms a thick batter. Carefully fold in blueberries.

Step 6

Spoon batter evenly into muffin cups, filling about 4/5 of the way up. If you've got a few extra blueberries, press them down gently on top of each muffin, then sprinkle generously with streusel.

Step 7

Bake muffins until a toothpick inserted comes out clean, about 11-13 minutes. Remove muffins from oven and let stand for 5 minutes before transferring to a cooling rack. Serve warm or at room temperature.