Step 1In a medium frying pan, cook the bacon over medium heat until cooked but not crispy, 10 to 12 minutes, stirring frequently. Remove the bacon to a paper towel-lined plate or pan, to remove excess fat.
Step 2In a large bowl, whisk together the flour, sugar, baking powder, baking soda and salt.
Step 3Using a pastry cutter or fork, cut in the diced butter, until it resembles small peas. Stir in the bacon, then one-fourth cup plus 2 tablespoons of maple syrup and the buttermilk until the dough just comes together (it will still be clumpy). Be careful not to overwork the dough.
Step 4On a lightly floured surface, gently press or roll the dough to 1-inch thickness. Cut the biscuits using a 2-inch round cutter; you should have 24 biscuits. Place 12 biscuits on each of two parchment-lined baking sheets, spaced 2 inches apart. Freeze the trays just until the biscuits are chilled, about 10 minutes.
Step 5Heat the oven to 350 degrees. While the biscuits are chilling, prepare the egg wash: In a small bowl, whisk together the egg yolk, egg and cream. Brush the chilled biscuits with egg wash and top each with a pinch of fleur de sel.
Step 6Bake the biscuits until they just begin to brown, about 25 minutes (you should easily be able to pick the biscuits up off the tray). Remove the tray from the oven. Quickly drizzle 1 teaspoon of the remaining maple syrup over each biscuit, then place the tray back in the oven for 3 minutes more. Serve while still warm.