Preheat oven to 425°F. Spray a jumbo 6 compartment muffin pan with nonstick cooking spray (preferably one that contains flour) or use muffin liners. Set aside. In a large bowl whisk the flour, baking powder, baking soda, salt, and ground cinnamon. In a medium bowl whisk the melted butter, vegetable oil, sugar, and eggs. Once combined, whisk in the sour cream, buttermilk, and vanilla extract. Whisk until smooth.
Pour the wet ingredients over the dry ingredients. Use a rubber spatula to stir to combine. When halfway combined, add the chocolate chips and mix until no flour streaks remain. Batter will be thick! Don’t overmix. Portion the batter into each muffin cup, filling all the way to the top. Sprinkle coarse sugar over the batter then bake at 425°F. for 5 minutes, then reduce the oven temperature to 350° and bake for an additional 25 minutes until the centers are set and the tops are golden in color.
Remove from the oven and let cool in the pan for 10 minutes. Remove and enjoy warm or at room temperature. Store leftovers at room temp for 4-5 days. Fridge for 1 week or freeze for up to 3 months.