Glazed cake doughnuts

Ingredients

• 1 cup flour
• 1/3 cup sugar
• 1/2 teaspoon baking soda
• 1 teaspoon baking powder
• 1/2 teaspoon salt
• 2 tablespoons cold butter
• 1/2 cup buttermilk
• 1 teaspoon vanilla extract
• 1 egg

glaze:

• 1 tablespoons milk
• 1/2 cup powdered sugar