Cream butter, brown sugar, and granulated sugar until light and fluffy with an electric mixer in a large bowl.
Add the egg, egg yolk, and vanilla extract, mixing until combined.
Whisk together the flour, baking soda, and salt. Gradually add to the wet ingredients.
Fold in the chocolate chips.
Cover and refrigerate the dough for 30 minutes.
Roll out the chilled dough on a lightly floured surface. Use a heart-shaped cookie cutter to cut out shapes.
Preheat the oven to 350°F. Place cookies on a parchment-lined baking sheet and bake for 10-12 minutes until golden.
If the cookies have spread recut them with the cookie cutter while they are still warm on the pan. The scraps are delicious! Leave them on the pan for 5 minutes before transferring to a cooling rack.
Drizzle with melted chocolate and top with sprinkles if desired.
Notes
Chill the Dough: Chilling helps prevent the cookies from spreading too much while baking.
Don’t Overmix: Mix until just combined to keep the cookies tender and chewy.
Watch the Oven: Bake until the edges are set but the centers still look slightly soft—this ensures a chewy center!
Quick Fix for Spreading: if your cookies still spread after baking even after chilling, remove them from the oven, re-cut them with the cookie cutter, and leave them on the warm baking sheet to set.