1-Preparing the Lemon Cookies: First, whisk the melted and cooled butter with granulated sugar in a large bowl until it turns thick and shiny this step helps build the base for your lemonade cookies. Next, whisk in the egg, vanilla extract, and fresh lemon juice until everything is smooth and well combined, which takes about 60 seconds. Then, fold in the flour, baking powder, cornstarch, lemon zest, and salt just until mixed, keeping the dough soft and ready for chilling.

2-Preparing the Lemon Cookies: After that, chill the dough for 2 hours to prevent spreading and ensure your cookies hold their shape. Once chilled, preheat your oven to 350ºF and line a baking sheet with parchment paper for easy cleanup. Divide the dough into 6 large portions, about 1/3 cup each, and shape them into disks that are roughly 2.5 inches in diameter and 7/8 inch tall.

3-Preparing the Lemon Cookies: Place the disks 3 inches apart on the baking sheet and bake for 15-16 minutes until they’re puffed and lightly golden on the edges, but don’t overbake to keep them soft. Let them cool completely before adding frosting this step is key for the best texture in your lemonade cookie recipe.

4-Making the Lemonade Frosting: Start by beating the softened butter on medium speed until it’s creamy and smooth, setting the stage for a fluffy frosting. Gradually add the powdered sugar while beating on low until it’s all mixed in, creating a base for your lemonade buttercream. In a small bowl, mix the milk or cream, optional lemonade-flavored drink mix, vanilla extract, lemon juice, and lemon zest until everything dissolves smoothly.

5-Making the Lemonade Frosting: Add this mixture to the buttercream and beat it together, then stir in yellow food coloring if you want that vibrant look. Adjust the consistency with 1-2 tablespoons of heavy cream or milk as needed, and beat on medium-high speed for 1-2 minutes until the frosting is light and fluffy. Finally, frost each cooled cookie with about 3 tablespoons of frosting, smoothing it out with a spatula, and top with optional lemon slices for extra flair.