Preheat oven to 375 degrees. Lightly butter 6-cupcake pan. With a rolling pin, flatten bread slices slightly and with a 4 1/4 inch cookie cutter, cut into 8 rounds. Cut each round in half, then press 2 halves into each cupcake cups, overlapping slightly and making sure bread comes up to edge of cup. Use extra bread to patch any gaps. Brush bread with remaining butter. In a large skillet, cook bacon over medium, until almost crisp, 4 minutes flipping once. (It will continue to cook in the oven.) Lay 1 bacon slice in each bread cup and crack an egg over each. Season with salt and pepper. Bake until egg whites are just set, 20-25 minutes. Run a small knife around cups to loosen toasts. Serve Immediately.