Preheat oven to 425°F. Prepare doughnut pan with vegetable pan spray.

In large bowl, whisk together flour, sugar, baking powder, nutmeg and salt. Add buttermilk, eggs and butter. Beat until just combined. Fold in 1 cup blueberries. Fill each doughnut cup approximately 2/3 full.

Bake 7-9 minutes or until the tops of the doughnut spring back when touched. Let cool in pan 5 minutes before removing to cooling grid to cool completely.

For glaze, puree remaining blueberries in blender or food processor. Strain puree; 1/4 cup juice should remain. Discard solids.

In small bowl whisk together blueberry juice and confectioners’ sugar until smooth. Cover tops of doughnuts with glaze.