Preheat the oven to 400°F. Generously grease the wells of the muffin pan with cooking spray or softened butter.

Whisk the flour, baking powder, baking soda, salt and pepper in a medium-sized bowl. Add the cheese and bacon and whisk again, or combine with your hands.

In a large bowl, combine the oil and sugar and whisk to combine. Add the eggs and yolk one at a time, whisking after each addition. Add the buttermilk, whisking a final time.

Add the dry ingredients to the wet ingredients, folding gently with a rubber spatula just until incorporated. Do not over mix.

Fill the muffin tins 3/4 of the way full. Bake for 10 minutes, rotate the pan and reduce the temp to 350°F and bake for another 5 minutes, or so. until a cake tester inserted in the center comes out clean or with a moist crumb.

Remove the muffins from the pan as soon as they are cool enough to touch by running a butter knife around the edges of each one. Serve warm with salted butter. The muffins are best the day they are made (and preferably warm from the oven) but can be stored, in an air-tight container on the counter, for a few days, or frozen. Reheat in a 350°F oven briefly before serving.