Step 1

Combine all the dry ingredients in a small bowl. Pour in the melted butter and mix until all the dry ingredients are moistened. Cover, and set aside.

Step 2

Preheat oven to 375 degrees F (190 degrees C) and line a muffin pan with paper liners, preferably tulip liners (*See note).

Step 3

Add the flour, baking powder, and salt into a medium size bowl and mix with a wire whisk to combine.

Step 4

Add the melted butter, sugar, and eggs to another medium size bowl and whisk vigorously with a wire whisk for about 30 seconds, until well combined. Add the yogurt, lemon zest, and vanilla extract and whisk for a few seconds more, until the batter is smooth.

Step 5

With a rubber spatula or wooden spoon, stir in the dry ingredients and then the berries. The batter will be very thick. If using fresh berries, fold them into the batter as gently as you can with a rubber spatula or wooden spoon. When mixing in frozen berries, I usually use my hands to fully incorporate them into the batter.

Step 6

If using tulip muffin liners, distribute the batter amongst 12 muffin cups. If using regular muffin liners, fill 18 - 24 muffin cups half full. The batter is very thick, so use your fingers or the back of a spoon to press the batter gently into each cup. Evenly distribute the crumb topping across all the muffins.

Step 7

If using tulip liners, bake for 28 - 32 minutes until a toothpick inserted in the center of one of the muffins comes out mostly clean. If baking slightly smaller muffins in regular muffin liners, bake for 18 -23 minutes.

Step 8

Let the muffins cool inside the pan placed on a wire rack for about 10 minutes then remove and serve. Or, let cool completely and wrap individually or store in an air-tight container.