1-First Step: Prep your skillet and oven. Crank the oven to 350 degrees F. Lightly butter a 10-12 inch oven-safe skillet. This prevents sticking and adds flavor. Mise en place: measure everything out. Chop graham crackers and chocolate bars into bite-size pieces. Got kids? Let them help here it’s mess-free fun. Prep time starts now; aim for 15 minutes total.

2-Second Step: Cream the wet ingredients. In a large bowl, beat 2 sticks (1 cup) softened butter, 1/2 cup brown sugar (or 3/4 for sweeter), and 1/4 cup granulated sugar until fluffy and combined. Add 2 large eggs one at a time, mixing well after each. Stir in 2 teaspoons vanilla extract until creamy. This base takes 2-3 minutes with a hand mixer or spoon. Smells amazing already, right? The brown sugar ratio keeps it balanced against the fillings.

3-Third Step: Mix in dry ingredients and chips. Add 2 1/4 cups all-purpose flour, 1 teaspoon baking soda, 1/2 teaspoon salt, and optional pinch of baking powder. Stir until just combined don’t overmix for tenderness. Fold in 1 cup chocolate chips. Dough will be thick and scoopable. If it feels dry, a splash of milk helps, but usually perfect.

4-Fourth Step: Layer the magic. Spread one third of the dough evenly into the skillet. Layer 4 squares graham crackers (bite-size), 8-10 marshmallows, and 2 broken chocolate bars over the dough. Top with remaining two-thirds dough, spreading gently. Some marshmallows peeking out? Totally fine they’ll bubble up gorgeously. Press lightly to seal edges.

5-Final Step: Bake, cool, and serve. Bake 20-22 minutes for doughy center or 22-25 minutes for set cookie. Ovens vary, so check at 20. Marshmallows bubble for visual wow. Cool 3-5 minutes in skillet. Sprinkle 1-2 ounces sea salt if using. Serve warm with ice cream scoops pure bliss. Total cook time 25 minutes, full 40. Yields 12 servings at 483 kcal each.