Step 1

Preheat the oven to 375℉/190℃. Line the muffin tin with liners and set aside.

Step 2

In a bowl add the butter, flour, and sugar. Mix together with your hands or a fork until a crumbly streusel forms. Set in the fridge to chill.

Step 3

Into a bowl add the flour, baking soda, baking powder, cornstarch, and cinnamon. Stir to combine and set aside.

Step 4

Into a large bowl add the white sugar, vanilla, yogurt, melted butter, oil, eggs, and lemon zest. Whisk together.

Step 5

Combine the dry and wet ingredients with a spatula until a soft muffin batter forms. Do not over-mix!

Step 6

Into the bowl with the mixed berries, add 1 tsp of flour and evenly coat the berries in it. This will prevent them from sinking as they bake.

Step 7

Add them into the muffin batter and stir to combine. Don't over-mix!

Step 8

Scoop the batter into the liners, filling them to the top. Sprinkle a handful of streusel on top of each one.

Step 9

Bake for 20-25 minutes, or until a toothpick inserted comes out clean.

Step 10

These muffins are such a treat! Enjoy!