Making Heart-Shaped Dulce de Leche Cookies is straightforward. Follow these steps for a guaranteed success:

1. Preheat the Oven: Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.
2. Combine Dry Ingredients: In a bowl, whisk together the flour, baking powder, and salt.
3. Cream Butter and Sugar: In another large bowl, beat the softened butter and granulated sugar until light and fluffy.
4. Add Egg and Vanilla: Mix in the egg and vanilla extract until well combined.
5. Mix Dry Ingredients: Gradually add the flour mixture to the butter mixture, stirring until a dough forms.
6. Chill the Dough: Wrap the dough in plastic wrap and refrigerate for at least 30 minutes to firm up.
7. Roll Out the Dough: On a lightly floured surface, roll out the chilled dough to about 1/4 inch thick.
8. Cut Heart Shapes: Use a heart-shaped cookie cutter to cut out cookies. Place half of the cookies on the prepared baking sheets.
9. Add Dulce de Leche: Spoon a small amount of dulce de leche onto the center of each cookie on the baking sheet.
10. Top with Second Cookie: Place the remaining heart-shaped cookies on top of the filled cookies, pressing gently to seal.
11. Bake: Bake in the preheated oven for 12-15 minutes, or until the edges are lightly golden.
12. Cool: Remove from the oven and let the cookies cool on the baking sheets for 10 minutes before transferring them to a wire rack to cool completely.
13. Dust with Powdered Sugar: Once cooled, dust the cookies with powdered sugar for a beautiful finish.

These steps ensure that your Heart-Shaped Dulce de Leche Cookies turn out perfectly every time.