Could you tell me how to prepare Hannah’s Skillet Cookie?
Here's a recipe for Hannah’s Skillet Cookie:

Ingredients:

Fruity Pebble Treats:

• 1/2 stick unsalted butter
• 4 cups mini marshmallows
• 1/4 teaspoon kosher salt
• 4 cups Fruity Pebbles cereal

Skillet Cookie:

• 1 stick unsalted butter, softened
• 1 1/4 cups brown sugar
• 2 teaspoons vanilla extract
• 1 large egg
• 2 large egg yolks
• 2 cups all purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon baking soda
• 1/2 teaspoon kosher salt
• 2 cups lucky charms cereal

For Serving:

• 2 tablespoons lucky charms mashmallows

Instructions:

1. Make the Fruity Pebbles Treats: Line an 8” x 8” (20 x 20 cm) baking pan with parchment paper and grease lightly with a nonstick baking spray.
2. Melt the butter in a medium pot over medium-low heat. Once melted, add marshmallows and salt, stirring frequently until completely melted and butter is incorporated, about 3–5 minutes. Remove from heat.
3. Add Fruity Pebbles cereal and stir to combine, until the marshmallow mix is distributed evenly. Spread in parchment-lined pan into an even layer, pressing down with a greased spatula, and let cool completely.
4. Once cooled, remove the Fruity Pebbles treat from the pan by lifting the parchment paper out and set on a cutting board. Cut into 1/2-inch (1.2 cm) squares.
5. Make the Skillet Cookie: Preheat the oven to 350°F (180°C).
6. In a large bowl, cream together the butter and brown sugar with an electric hand mixer on high speed until light and fluffy, 2–3 minutes. Add the vanilla, then add the egg and egg yolks, 1 at a time, beating on medium speed between each addition to combine. Scrape down the sides of the bowl with a spatula as needed.
7. In a medium bowl, whisk together the flour, baking soda, baking powder, and kosher salt.
8. Add the dry ingredients to the large bowl with the wet ingredients and mix on medium-low speed until just combined. Add the Lucky Charms cereal and mix on low speed until just evenly distributed, about 30 seconds.
9. Grease a 10-inch cast-iron skillet with nonstick cooking spray. Spread about one-third of the cookie dough evenly into the skillet, using a spatula to smooth out the dough. Add half of the Fruity Pebble Treat squares and press them down into the cookie dough. Spread the remaining two-thirds of the dough over the squares and smooth out as evenly as possible with a spatula.
10. Bake the cookie for 35–40 minutes, until the top is golden brown and the center is no longer jiggly when the pan is shaken.
11. Immediately after the cookie is removed from the oven, gently press the remaining Fruity Pebble Treat squares into the top of the cookie. Scatter Lucky Charms marshmallows over the top and carefully press those into the cookie surface. Let the cookie cool in the pan for 20 minutes.

Enjoy your Hannah’s Skillet Cookie!