Easy, moist, delicious muffins.
Preheat oven to 375℉
Add cupcake papers to the muffin tins
Wisk together in a medium bowl: flour, baking powder, salt, and cinnamon.
In a large bowl, mix with a baking spatula or wooden spoon: sugar, egg, yogurt, buttermilk, melted butter, lemon zest, and vanilla.
Cut the blackberries in half and add to a small bowl.
If the blackberries are very tart then add 1/8 cup of sugar into the blackberries and stir.
Combine the wet and dry mixture with a wooden spoon until just combined.
Fold the berries into the the mixture.
Fill the muffin papers to barely level with the edge of the cups of the tin.
Bake for 15-18 minutes.
Let the muffins cool in the tin until they are cool enough to remove without burning your fingers.
Eat with lots of butter.