Sandwich cookies with dulce de leche

Ingredients:

• 330 g unsalted butter, room temperature
• 1 cup powdered sugar
• 2 tbsp. granulated sugar
• 1 tsp. grated orange zest
• 0.5 tsp vanilla extract
• 3 1/4 cups all-purpose flour, plus extra for dusting
• 1/4 teaspoon salt
• 1.5 tbsp. dulce de leche

Preparation:

1. In a large bowl, beat the butter, granulated sugar, powdered sugar, and orange zest with a mixer on medium-high speed until light and fluffy, about 3 minutes. Add the vanilla extract and beat until smooth. In a medium bowl, combine the flour and salt, then add to the butter mixture and beat until smooth. Scrape down the sides of the bowl, then beat for another 20 seconds. Wrap the dough in plastic wrap and refrigerate for 30 minutes.
2. On a lightly floured work surface, roll the dough out to a thickness of 0.5 cm. Using a 7.5 cm cookie cutter, cut out as many circles as possible. Arrange the circles on two parchment-lined baking sheets. Gather the scraps, mix them together, roll them out, and cut out more circles. If the dough begins to soften, return it to the refrigerator for a while.
3. Preheat oven to 325°F (160°C). Using a 3-inch cookie stamp, stamp each cookie with the desired shape. Refrigerate for at least 15 minutes.
4. Bake the cookies until light golden brown around the edges, about 10 minutes. Let cool on the baking sheets for 5 minutes, then transfer to wire racks to cool completely.
5. Place dulce de leche in a pastry bag and snip off the corner. Pipe dulce de leche onto half of the cookie (the side without the stamp). Top with another cookie, stamped side up.