Shortbread Cookie Bars - Recipe from Scratch

      These Shortbread Cookie Bars are particularly tender and have a melt-in-your-mouth quality due to a crucial substitution: using confectioners' sugar instead of granulated sugar. Since it dissolves quickly into the softened butter, confectioners' sugar yields a remarkably smooth dough and a finer, more delicate texture. Similar to traditional shortbread, the dough is easy to prepare—there's no need for chilling or rolling. You simply press it into the pan, which reduces gluten formation and results in that signature sandy texture. Docking the dough with a fork serves a purpose beyond aesthetics; it allows steam to escape, ensuring that the slab bakes uniformly rather than puffing up in certain areas.

      **Shortbread:**

      - 1½ cups (340 grams) salted butter, softened

      - 1 cup (120 grams) confectioners’ sugar

      - 1 tablespoon (13 grams) vanilla extract

      - 3 cups (375 grams) all-purpose flour

      - 1 teaspoon kosher salt

      **Buttercream:**

      - 1 cup (227 grams) salted butter, softened

      - 4 cups (480 grams) confectioners’ sugar

      - ½ teaspoon kosher salt

      - 2 tablespoons (30 grams) whole milk

      - 2 teaspoons (8 grams) vanilla extract

      **Garnish:**

      - assorted sprinkles

      Preheat the oven to 325°F (170°C). Line an 8-inch square baking pan with parchment paper, ensuring that some excess hangs over the sides of the pan. For the shortbread: In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and confectioners’ sugar on medium speed until creamy, about 3 to 4 minutes, making sure to stop and scrape the bowl's sides. Mix in the vanilla.

      In a separate medium bowl, whisk together the flour and salt. With the mixer on low speed, gradually add the flour mixture to the butter mixture, beating until the dough comes together, pausing to scrape the bottom and sides of the bowl. Press the dough into the prepared pan and prick it all over with a fork. Bake until lightly browned and an instant-read thermometer inserted into the center reads 200°F (93°C) to 205°F (96°C), which should take about 30 to 35 minutes. Allow to cool completely in the pan on a wire rack.

      For the buttercream: In the bowl of a stand mixer fitted with a paddle attachment, beat the butter on medium speed until creamy, about 1 to 2 minutes. With the mixer on low speed, gradually mix in the confectioners’ sugar and salt, beating until smooth and stopping to scrape the bowl's sides. Add milk and vanilla, mixing until smooth once again and scraping the bowl as needed. Increase the mixer speed to high and beat until light and fluffy, approximately 2 minutes.

      Spread the buttercream over the cooled shortbread. If you like, decorate with sprinkles. Use the extra parchment as handles to lift the bars from the pan, then cut into bars. Store in an airtight container for up to 3 days.

      We’d love to hear how it turned out!