Enjoy fresh doughnuts in the morning with this make-ahead recipe. Chill the dough overnight so all that's left is rolling and cutting the dough, and frying the doughnuts.
Combine mix, baking soda, cinnamon in bowl. Whisk eggs, sugar, sour cream, vanilla in second bowl. Stir dry mixture into egg mixture. Place on floured surface; gently knead in chips. Shape into disk; wrap. Chill 3 hours or overnight.
For frosting, heat cream in small saucepan until steaming. Pour over chocolate in a bowl; stir until smooth.
Unwrap dough; pat 1/2 inch thick on floured surface. Cut out doughnuts using a floured 2 1/2-inch cutter, and a 3/4-inch cutter for holes.
Heat 2 inches oil in deep pan to 365°F. Slide a few doughnuts and holes into oil; fry until dark golden, 1 to 2 minutes per side. Drain on paper toweling. Repeat.
Dip in frosting. Or pour glaze over both sides of doughnuts. (Or dust doughnuts with confectioners' sugar.)