Ingredients:

  • 1¾ cups (220 g) all-purpose flour, spooned and leveled
  • ½ cup (100 g) granulated sugar
  • 2 tsp (8 g) baking powder
  • ½ tsp (3 g) fine salt
  • ½ cup (115 g) unsalted butter, melted and slightly cooled
  • 1 large egg (50 g), at room temperature
  • ¾ cup (180 ml) whole milk
  • 1 tsp (5 ml) vanilla extract
  • ¾ cup (130 g) semi-sweet chocolate chips, divided
  • ⅓ cup (40 g) graham cracker crumbs (about 3 full graham sheets)
  • 2 tbsp (25 g) packed light brown sugar
  • 2 tbsp (28 g) unsalted butter, melted
  • 1 cup (50 g) mini marshmallows

Instructions:

  1. Preheat the oven to 400°F (200°C). Set the rack in the center of the oven.
  2. Line a 12-cup muffin tin with 12 paper liners.
  3. In a small bowl, stir together the graham cracker crumbs, brown sugar, and 2 tbsp melted butter until the mixture looks like damp sand. Set aside.
  4. In a large bowl, whisk the flour, granulated sugar, baking powder, and salt until evenly combined.
  5. In a medium bowl, whisk the ½ cup melted butter, egg, milk, and vanilla until smooth and no streaks of egg remain.
  6. Pour the wet mixture into the dry ingredients. Fold with a spatula for 15 to 20 strokes, stopping while a few flour streaks remain. The batter should look thick, lumpy, and slightly glossy.
  7. Add ½ cup (about 85 g) of the chocolate chips and fold just until distributed. Reserve the remaining chips for the tops.
  8. Divide the batter among the 12 liners, filling each about two-thirds full.
  9. Press 3 or 4 mini marshmallows lightly into the top of each muffin so they sit just below the surface.
  10. Sprinkle the remaining chocolate chips and the graham crumble evenly over each muffin.
  11. Bake for 15 to 17 minutes, until the tops are golden, the edges pull slightly from the liners, and a toothpick inserted into the center comes out with moist crumbs or melted chocolate, not wet batter.
  12. Cool in the tin for 5 minutes, then move the muffins to a wire rack. Serve warm or cool completely.