Preheat oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Roll out the toast slices as thin as possible with a dough roller. Brush each slice with 1 tsp. butter.
Press the toasts with the butter side down into the greased recesses of a muffin tray (12 recesses). Place 1 slice of bacon in each of the toast hollows. Beat 1 egg into each trough.
Bake in a hot oven for 10-15 minutes and let it rest for a short time. Carefully lift out of the trays. Season with salt and pepper.