Preheat the oven to 430F. As soon as you put muffins in the oven lower to 400F.
- Combine dry ingredients in a bowl, sifting your flour.
- In another bowl mix eggs, egg yolks; then add melted butter, vanilla extract, oil and buttermilk.
- Add your wet ingredients to the dry ingredients. Mix just until all are just combined.
- Add chocolate chunks.
- Fill the muffin liners until 3/4 full.
- Bake for 20 minutes.
- Cool on a wire rack and enjoy!