Blueberry Lemon Corn Muffins

From Epicurious Frozen blueberries work here as well. Just keep them frozen until you make them to prevent bleeding into the batter.
1/2 stick (1/4 cup) unsalted butter
3/4 cup all-purpose flour
1 1/2 teaspoons baking powder
1/2 cup yellow cornmeal
1/2 cup plus 1 tablespoon sugar
1 tablespoon freshly grated lemon zest
1/2 cup whole milk
2 large egg yolks
1/2 cup blueberries

Preheat oven to 375°F. and line six 1/3-cup muffin cups with paper liners.
Melt butter and cool.
Into a large bowl sift together flour and baking powder and whisk in cornmeal, 1/2 cup sugar, lemon zest, and a generous pinch salt.
In a bowl whisk together melted butter, milk, and yolks and add to flour mixture with half of blueberries, gently stirring until just combined.
Divide batter evenly among cups (batter will fill cups) and press remaining blueberries into tops of muffins.
Sprinkle tops of muffins evenly with remaining tablespoon sugar.
Bake muffins in middle of oven about 15 minutes, or until tops are golden and a tester comes out clean.
Remove muffins from cups and cool on a rack.
Muffins keep in an airtight container at room temperature 2 days (if they last that long)