Preheat oven to 375 °F (190 °C). Using a sharp serrated knife, cut a grid pattern into the top of the loaf, slicing down nearly to the bottom but not cutting through it, creating deep pockets.

Carefully stuff jalapeño slices into every crevice of the grid, pressing them deep. Follow by tucking in slices of cold cream cheese. Sprinkle scallions evenly into the pockets, then top the loaf with grated cheddar. Season lightly with salt and pepper.

Place the filled loaf on a baking sheet and bake for 15–20 minutes, until the cheese melts and the jalapeños soften.

Remove from oven and serve warm—pull apart each square for gooey cheesy bites.