Heat oven to 350°F. Line two baking sheets with parchment paper.
Cream softened butter with 2/3 cup powdered sugar until light and fluffy, about 2 minutes.
Beat in lemon zest, 1 1/2 tablespoons lemon juice, vanilla, and salt until smooth.
Add flour and cornstarch. Mix on low just until a soft dough forms; do not overmix.
Scoop 1-tablespoon portions, roll into balls, and space 2 inches apart on prepared sheets.
Bake 9–11 minutes until edges look set but not browned. Cool on the sheet 5 minutes.
Whisk 1 1/2 cups powdered sugar, 3 tablespoons lemon juice, zest, and milk until smooth and pourable.
Dip warm cookies top-side into the glaze or spoon it over. Let set until the glaze firms up.
Notes
Try adding a pinch of poppy seeds to the dough for a subtle crunch, or swap vanilla for almond extract for a twist. Store airtight at room temperature for 3–4 days, or freeze glazed cookies in a single layer until set, then stack with parchment.This recipe is an original creation inspired by classic Easy Lemon Meltaway Cookies flavors. All ingredient ratios and instructions are independently developed.