Preheat oven to 350 degrees F. Line a baking sheet with aluminum foil. Place a wire rack on top and set aside.
Combine maple syrup with dijon mustard and black pepper. Lay bacon on the wire rack and brush the syrup evenly on each bacon strip. Bake for 15 minutes. Flip the bacon over, brush on the remaining syrup and bake another 10 minutes. Remove from the oven and transfer the bacon to a cutting board. Cut into bite size pieces.
Increase oven to 400 degrees F.
Mix together dry ingredients in a large bowl including flour, sugar, salt, baking powder, and baking soda. Add butter and use a pastry cutter, a knife or your hands to mix until the mixture resembles coarse meal. Add buttermilk and mix until just combined. Fold in chopped bacon.
Lightly dust flour onto work surface. Divide dough in half. Working with one batch at a time, shape dough into a ¾ inch thick square. Cut the dough into 8 equal pieces. Lay them on a baking sheet lined with parchment paper and repeat with the remaining dough.
Brush the tops of scones with buttermilk and sprinkle with coarse sugar. Bake for 15-20 minutes or until golden brown. Serve warm.