In a large bowl, beat ½ cup room-temperature butter, ½ cup sugar, and 1 teaspoon vanilla extract until light, creamy, and smooth.
Mix in 1 large egg, beating until fully incorporated and the mixture is smooth.
Add 1¾ cups all-purpose flour and gently mix with a spatula just until a smooth dough forms. Do not overmix.
Wrap the dough tightly in plastic wrap and shape it into a flat rectangle. Freeze for at least 30 minutes to make the dough easier to roll and cut.
Remove the dough from the freezer and let it sit for a few minutes if very firm. On a lightly floured surface, roll the dough to about ¼ inch thick. Cut out heart shapes using cookie cutters.
Place the cookies on a baking sheet lined with parchment paper, leaving space between each cookie.
Preheat the oven to 350°F (180°C). Bake the cookies for 7–8 minutes, just until the edges are set. The cookies should remain pale on top.
Let the cookies cool on the baking sheet for a few minutes, then transfer them to a wire rack to cool completely.
Melt ½ cup melting chocolate according to package instructions. Drizzle over the cooled cookies and immediately add Valentine’s Day–themed sprinkles before the chocolate sets.
Notes
Butter: Use room-temperature butter so the dough mixes smoothly.
Rolling the Dough: Lightly flour your surface and roll the dough evenly to about ¼ inch thick.
Chilling: If the dough becomes soft or sticky, place it in the freezer for a few minutes to make it easier to handle.
Baking: Bake just until the edges are set. The cookies should stay pale on top and not brown.
Egg Size: Use a large egg. If your egg is small, add 1–2 teaspoons of milk to balance the dough.
Flavor Variations: Add lemon zest, orange zest, or almond extract for a fun flavor twist.
Decorating: Add sprinkles right after icing or chocolate so they stick properly.
Make Ahead: The dough can be made up to 48 hours ahead or frozen for up to 2 months.
Storage: Store baked cookies in an airtight container for up to 1 week.