Sour Cream Coffee Cake Muffins

Instructions

1. Step 1

   Gather the ingredients. Preheat the oven to 400 F and place muffin liners in a 12-cup muffin pan.

2. Step 2

   For the crumb topping and swirl, mix all of the ingredients together in a small bowl with a fork, or your fingers, until thoroughly combined and refrigerate until ready to use.

3. Step 3

   For the muffins, in a large mixing bowl, whisk together the sugar, oil, and vanilla until well combined.

4. Step 4

   Add the egg and yolk, one at a time, whisking after each addition.

5. Step 5

   Add the sour cream and whisk again.

6. Step 6

   In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.

7. Step 7

   Gently fold the the dry ingredients into the wet ingredients with a flexible spatula.

8. Step 8

   Fill each muffin cup halfway with batter, about 1 1/2 tablespoons.

9. Step 9

   Sprinkle two teaspoons of the topping/swirl mixture evenly over each muffin.

10. Step 10

    Add about 1 1/2 tablespoons of batter to each muffin and spread the batter over the swirl mixture with a small offset spatula, butter knife, or the back of a spoon.

11. Step 11

    Sprinkle the remaining crumb mixture evenly on top of each muffin, about, 1 1/2 teaspoons, per muffin, pressing down lightly.

12. Step 12

    Bake for 20 to 25 minutes, rotating the pan and turning the oven down to 350 F at the halfway point. The muffins are ready when a wooden skewer inserted in the center comes out with a moist crumb or two. Let cool to room temperature before removing from the pan.

13. Step 13

    Dust with confectioners' sugar before serving. The muffins will keep, tightly wrapped in plastic wrap, on the counter for up to 3 days.