Preheat your oven to 350°. Line a muffin tin with paper liners. This recipe makes 24 regular muffins or 12 jumbo muffins.
Mix the melted butter, granulated sugar, and brown sugar together. Then stir in the eggs.
Add the vanilla, lemon peel and milk.
In another bowl, stir the dry ingredients together. Add the dry ingredients to the wet ingredients, stirring until just combined. Don't overmix, or you'll have chewy muffins!
Then, gently stir in the berries.
Divide the batter evenly between the muffin cups, filling them about 3/4 full.
Bake regular-sized muffins for 15-17 minutes, and jumbo muffins for 18-20 minutes. Test for doneness with a toothpick.
After baking, place the muffins on a cooling rack to cool completely before storing in an airtight container. Store in the refrigerator for up to one week, or in the freezer for up to three months. Reheat in the microwave to bring back that fresh-from-the-oven taste!