Prep the pan: Heat the oven to 350°F (175°C). Generously butter a 12-cup muffin tin or line with parchment liners. Greasing well helps the muffins release cleanly.

Cube the bread: Use slightly stale bread for best texture. Cut into 1-inch cubes. If your bread is soft, spread the cubes on a sheet pan and toast at 300°F for 8–10 minutes to dry them out slightly.

Make the custard: In a large bowl, whisk eggs, milk, maple syrup (or sugar), vanilla, cinnamon, nutmeg, and salt until smooth. Whisk in the melted butter until combined.

Toss the bread: Add the bread cubes to the bowl and fold gently until every piece is coated. Let sit for 5–10 minutes to soak. If the mixture looks dry, splash in 2–3 tablespoons more milk.

Choose your path: For classic muffins, proceed as is. For blueberry muffins, gently fold in the floured blueberries to help prevent sinking and streaking.

Fill the tin: Divide the mixture among the muffin cups, mounding slightly. Press down lightly with the back of a spoon to compact. Sprinkle with coarse sugar if you like a crunchy top.

Bake: Bake 22–28 minutes, until the tops are golden and the centers feel set when pressed. A toothpick should come out with moist crumbs but not wet custard.

Cool briefly: Let the muffins rest in the pan for 5 minutes, then run a thin knife around the edges to release. Transfer to a rack. Dust with powdered sugar if desired.

Serve: Enjoy warm with maple syrup, a pat of butter, or a dollop of yogurt. They’re also great at room temperature.