Preheat your oven to 350 degrees. In a large bowl or using your stand mixer, beat together the egg, oil, sugar, flour, baking powder, soda, and vanilla & butter flavorings until smooth.Beat in the buttermilk, then spoon a small amount of the batter into the bottom of a muffin tin lined with cupcake wrappers. Spoon about a tablespoon of Nutella into the center of the muffin cup, then cover with a second spoonful of batter.Bake for about 15-17 minutes, or until the muffins are a light golden colored and they spring back when touched with your finger. Remove from oven and allow to cool for about 10 minutes in the pan. Remove to wire rack and allow to cool to room temp. Drizzle warm Nutella across the top of each muffin. So yummy!