1. Prepare for Baking: Setting the Stage for Success

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Line Baking Sheet: Line a large baking sheet with parchment paper or a silicone baking mat (Silpat).

2. Cream Together Butter and Sugars: The Foundation of Flavor and Texture

1. Combine Butter and Sugars: In a medium mixing bowl, combine the slightly softened butter, brown sugar, and granulated sugar.
2. Cream: Using a rubber spatula, cream the butter and sugars together until they are well combined and the mixture is relatively smooth. You can also use an electric mixer on a low setting if desired.
   • Tip: The butter should be softened but still slightly cool to the touch for optimal creaming.

3. Incorporate Egg and Vanilla: Adding Moisture and Flavor

1. Add Egg and Vanilla: Add the egg and vanilla extract to the creamed butter and sugar mixture.
2. Mix: Mix thoroughly until everything is smooth and well incorporated.

4. Combine Dry Ingredients: Ensuring Even Distribution

1. Add Dry Ingredients: Add the flour, cornstarch, baking soda, and salt over the wet ingredients.
   • Tip: For best results, measure the flour by fluffing it up in its container, then spooning it into the measuring cup and leveling it off with a straight edge.
2. Stir: Stir the dry ingredients into the wet ingredients until just combined. Be careful not to overmix. The dough will be thick.

5. Fold in M&M’s and Oreos: Adding the Festive Mix-Ins

1. Add M&M’s and Oreos: Add the Valentine’s Day M&M’s and the roughly chopped Oreo pieces to the cookie dough.
2. Fold: Gently fold in the M&M’s and Oreos using a rubber spatula until they are evenly distributed throughout the dough.

6. Shape and Bake the Cookies: Creating Large, Bakery-Style Treats

1. Scoop Dough: Use a large cookie scoop (approximately ¼ cup or 4 tablespoons) to portion out the cookie dough. This will create about 10 large cookies.
2. Place on Baking Sheet: Place the scoops of dough on the prepared baking sheet, leaving ample space between each one (about 2-3 inches) to allow for spreading.
3. Bake: Bake for 13 minutes.
   • Check for Doneness: The cookies should look slightly underdone or even a bit gooey in the middle. This is what you want! They will continue to bake as they cool on the baking sheet.
4. Optional Swirling: The recipe author suggests using a large, round cookie cutter to swirl around the just-baked cookies as soon as they come out of the oven, which helps to create a perfectly round shape.

7. Cool and Enjoy: Allowing the Cookies to Set

1. Cool on Baking Sheet: Let the cookies cool on the baking sheet for at least 5 minutes. This allows them to firm up slightly and prevents them from breaking when transferred.
2. Transfer to Wire Rack: Carefully transfer the cookies to a wire rack to cool completely.