1 1/2cupsfresh blackberries or 2 1/2 cups frozen unsweetened blackberriesunthawed
Instructions
Preheat oven to 375 degrees F. Line a muffin tin with 12 paper liners.
To make the topping:
In a small bowl, stir together the brown sugar, flour and lemon zest. Cut butter into 1/2 inch pieces and sprinkle over mixture. Using a pastry blender, cut the butter into the flour mixture until butter is oat sized. Add the nuts and stir to combine. Set aside.
To make the muffins:
In a large mixing bowl, stir together the flours, sugar, baking powder, baking soda, cinnamon, lemon zest and salt.
In a small mixing bowl, combine the egg, yogurt, melted butter and vanilla extract. Pour the yogurt mixture into the flour mixture and stir just until evenly mixed. The batter will be slightly thick and lumpy. Sprinkle with the blackberries and gently fold in with a large rubber spatula just until evenly distributed. Be careful not to break up the fruit. Do not over-mix.
Divide the batter evenly among the prepared muffin cups. Top each muffin with topping, dividing evenly. Bake until the muffins are golden and a toothpick inserted into the center comes out clean, 22 to 25 minutes. Allow to cool in the pan for 10 minutes then transfer to a wire rack to cool completely.
Notes
Store the muffins in a sealed container for up to 3 days.