Whisk together the flour, sugar, baking powder, soda, sea salt, and cinnamon in a medium bowl. Measure out the buttermilk into a liquid measuring cup and add the egg; whisk together. Pour the buttermilk mixture into the dry ingredients; whisk until moistened. Add the butter and whisk until smooth.
Refrigerate the batter overnight (or for up to 2 days). When you’re ready to make the waffles, preheat a waffle iron. Stir in the pecans to the batter. (NOTE: My waffle iron makes thinner, crispier waffles, though I’m sure this recipe would be delicious in a Belgian waffle maker.)
Spray your waffle iron with nonstick cooking spray (or lightly brush with oil or butter) and add a heaping 1/3 cup of batter. Close the waffle iron and cook for about 3 minutes or until the green light comes on. I usually let it cook slightly longer than recommended because I like mine extra-crispy!
Serve the waffles with butter, maple syrup, chopped pecans, and peaches. (They are also really delicious with a dollop of Greek yogurt!)
*Feel free to add substitute half of the flour with whole wheat flour: so 1/2 cup all-purpose flour and 1/2 cup whole wheat flour. Or, if you’re gluten-free, substitute all of the flour with a GF flour mix.