Cinnamon Buttermilk Muffins

7 Tbs. unsalted butter, at room temp
2/3 cup sugar
1 egg
1 1/2 cups all-purpose flour
1 1/2 tsp. baking powder
1/2 tsp. baking soda
1/2 tsp. salt
1/2 tsp. freshly grated nutmeg (or 3/4 teaspoon ground Cinnamon)
1/2 cup buttermilk
1 1/2 tsp. vanilla

For the Struesel:
2 T flour 

1/3 cup brown sugar 

1/2 tsp ground cinnamon

1 T cold butter

Preheat an oven to 350°. Grease 9 standard muffin cups or linewith paper liners. 

To make the muffins, in the bowl of an electric mixer fitted with the flat beater, combine the butter and sugar and beat on medium speed until light and fluffy. Add the egg and beat well until pale and smooth.

In another bowl, stir together the flour, baking powder, baking soda, salt and nutmeg. Add to the butter mixture in 2 additions, alternating with the buttermilk and vanilla. Stir just until evenly moistened. The batter will be slightly lumpy.

Spoon the batter into the prepared muffin cups, filling each ¾ full.

To make the topping, in a small bowl, mix the flour, brown sugar and cinnamon. Cut in butter with a pastry blender or forks until mixture resembles cornmeal. Gently sprinkle topping evenly over batter in prepared muffin tin. Gently press down topping slightly. 

Bake until the muffins are golden and springy to the touch and a toothpick inserted into the center of a muffin comes out clean, 20 to 25 minutes. Transfer the pan to a wire rack and let cool for 5 minutes. Unmold the muffins and let stand until cool enough to handle.
Yield: 9-10 muffins