Add the potatoes to the boiling water and cook 4 minutes. Remove with a slotted spoon and carefully transfer to a baking tray; let cool slightly. Pat the potatoes dry, then insert 3 pieces of the frozen bacon into the cuts of each potato, spacing the bacon evenly and letting it poke out of the top. Melt 5 tablespoons butter and brush generously over the potatoes and in the cuts. Reserve any excess butter for basting. Season the potatoes with salt and pepper.