Position an oven rack in the center of the oven and preheat to 400 degrees F. Line a standard 12-cup muffin pan with paper liners.
In a large nonstick skillet, cook the bacon, over medium heat until crisp and brown. Transfer the bacon to paper towels; drain and cool.
In a large bowl, whisk together the buttermilk, hot sauce and eggs. Combine the cornmeal, flour, sugar, baking powder, salt and pepper in a food processor. Drop in the cold butter cubes. Using on/off turns, blend until the butter is cut in finely and the mixture resembles a coarse meal. Pour the dry ingredients over the buttermilk mixture. Scatter the bacon and green onions over the batter. Using a thin, flexible spatula, fold the batter together, scraping up the liquids from the bottom each time and turning the bowl as you fold. Do not over-fold; some dry patches are fine. Using a rounded 1/3 cup of batter for each muffin, fill the paper liners.
Bake until puffed and browning at edges, and a tester inserted into the center comes out clean, 18 to 20 minutes. Let the muffins stand 5 to 10 minutes. Twist each muffin in place to loosen the edges from the pan. Lift the muffins out onto a rack and cool.