Preparation

• Preheat oven to 350˚F. Line a 12-cup muffin pan with paper liners.
• Make the crumb topping by combining the melted butter, sugar, flour, oats, and salt. Stir with a fork until crumbs form. Set aside.
• Combine flour, baking powder, and salt in a medium bowl. Set aside.
• If using frozen blueberries, place them in a small bowl and return to freezer until ready to use. If using fresh, place in a small bowl and set aside.
• In the bowl of an electric mixer, beat the butter for 1 minute until soft and fluffy. Add sugar and continue to beat for 3 minutes.
• Add eggs, one at a time, and beat just until incorporated. Add buttermilk, vanilla, and lemon zest and mix on low until combined.
• Remove bowl from mixer. Add flour mixture and stir by hand until flour disappears. Do not overmix.
• Gently stir in blueberries.
• Divide mixture evenly in the prepared muffin pan. Sprinkle with the crumb topping.
• Bake at 350˚F for 22 to 25 minutes or until light golden and a toothpick inserted into the center comes out clean.
• Allow muffins to cool for 5 minutes in the pan before removing to a wire rack. Drizzle lightly with the lemon glaze.
• For the lemon glaze, combine powdered sugar and lemon juice in a medium bowl. Stir until smooth.