Make the Dough

1. Preheat Oven: Begin by preheating your oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone mats to prevent sticking.
2. Cream the Butter and Sugars: In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy. This will take about 3 minutes with an electric mixer. The fluffier the mixture, the better the texture of the cookies!
3. Add Eggs and Vanilla: Beat in the eggs, one at a time, followed by the vanilla extract. Mix until well combined.
4. Combine Dry Ingredients: In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet mixture, stirring until just combined.

Mix in the Fun Stuff

1. Add the Mix-ins: Gently fold in the chocolate chips, mini marshmallows, heart-shaped sprinkles, candy hearts, and nuts (if using). Be careful not to overmix—just a gentle fold will do.
2. Scoop the Dough: Use a cookie scoop or tablespoon to drop rounded balls of dough onto the prepared baking sheets. Leave about 2 inches of space between each cookie to allow for spreading.
3. Flatten Slightly: If you want slightly flatter cookies, press down gently on each dough ball with the back of a spoon or your fingers. This step is optional, but it helps the cookies bake more evenly.

Bake the Cookies

1. Bake: Place the baking sheets in the oven and bake for 12-15 minutes, or until the edges of the cookies are golden brown. Keep an eye on them toward the end so they don’t overbake. The cookies will continue to firm up as they cool.
2. Cool: Remove the cookies from the oven and let them cool on the baking sheets for a few minutes. Then, transfer them to a wire rack to cool completely.