Preheat oven to 425F degrees. Spray your muffin tin of choice with non-stick spray or line with muffin liners. Set aside.

In a large bowl, mix together flour, baking powder, salt, cinnamon, and nutmeg. Set aside.

In a medium bowl, whisk together eggs and sugar until combined. Mix in melted butter, oil, milk, and vanilla until combined. Fold wet ingredients into dry ingredients and mix everything together by hand with a wooden spoon. Avoid overmixing. Gently mix until all the flour is off the bottom of the bowl and no big pockets of flour remain. The batter will be thick and somewhat lumpy. Fold in the chocolate chips.

Divide batter among prepared muffin tins, filling all the way to the top. Top with a sprinkle of coarse sugar, if desired. If making jumbo muffins: Bake at 425F degrees for 5 minutes. Reduce oven temperature to 375 and continue to bake for 25-26 minutes until tops are lightly golden and centers appear set. If making standard-size muffins (makes about 15-16) Bake at 425F degrees for 5 minutes, reduce oven temperature to 375 and continue to bake for 12-13 minutes. Allow to cool for 10 minutes in the pan before enjoying. Muffins taste best fresh the same day. Store muffins at room temperature in an airtight container for up to 5 days. Muffins freeze well, up to 3 months.