Preheat oven and cook bacon: Preheat oven to 200°F. In a large cast-iron or nonstick skillet or on a griddle, cook bacon over medium-high until fat is rendered and bacon is browned on one side, 5 to 6 minutes. Flip and cook until golden and crisp on underside, 1 to 3 minutes.

Transfer bacon to paper towels: Drain bacon on paper towels; pour off all but 1 teaspoon fat from skillet (reserve for another use).

Combine dry ingredients: In a bowl, whisk together flour, sugar, baking powder, baking soda, and salt.

Combine wet ingredients: In another bowl, whisk together buttermilk, melted butter, and egg.

Combine wet and dry ingredients: Whisk flour mixture into buttermilk mixture just until moistened, with small to medium lumps remaining.

Heat skillet and cook bacon pancakes: Heat skillet over medium. Cook pancakes in batches: Space slices of bacon evenly around the skillet, leaving space for pancake batter. Pour ¼-cupfuls batter over each slice. Cook until some bubbles appear on top of pancakes and a few have burst, about 2 minutes.

Flip pancakes and cook other side: With a spatula, carefully flip pancakes and cook until browned on underside, about 2 minutes.

Serve or keep warm while other pancakes cook: Transfer to a platter, bacon side up, and loosely tent with foil. Keep pancakes warm in oven and repeat with remaining batter, adding more bacon fat if needed. Serve with pure maple syrup, if desired.