Chocolate Sugar Cookies with Pink Frosting

Preheat the oven to 375 (F) and line two cookie sheets with parchment paper.
In a medium bowl, whisk together 1 1/2 cups all-purpose flour, 1/2 cup cocoa powder, 1 teaspoon baking powder, and 1/2 teaspoon salt. Set aside.
In the bowl of a freestanding electric mixer fitted with a paddle attachment, combine 1/2 cup unsalted butter and 1 1/2 cups granulated sugar. Beat on medium-high speed at least 5 minutes, until pale and fluffy. Reduce the mixer speed to its lowest setting and add 1/2 cup vegetable shortening until fully incorporated. Add 1 egg and 1 1/2 teaspoons vanilla extract, and continue mixing until fully incorporated and the mixture looks creamy. Gradually add the flour mixture (from the 2nd step) a quarter cup at a time, and continue mixing until just combined — be careful not to overmix, or you'll have tough cookies and I'll cry for you!
Use a 2 1/2-inch cookie scoop to drop dough onto the prepared baking sheets, spacing each dough ball about 4 inches apart. Once you've scooped out the dough balls, run your hand under cold water and press down the top of each dough ball (having a damp hand will prevent the dough from sticking to your skin). Bake until the edges are firm, between 14 to 18 minutes (see baker's notes). Once the cookies are finished, transfer the baking trays to wire racks and allow to cool on the baking sheets completely.

When the cookies are completely cool, make the frosting. Combine 4 tablespoons unsalted butter, 1/2 cup plus 2 tablespoons sweetened condensed milk, and 1/4 scant teaspoon of kosher salt in the bowl of a freestanding electric mixer fitted with a whisk attachment, and whisk on medium-high speed until smooth.
Once the mixture is smooth, lower the mixer's speed to its lowest setting and whisk in 3/4 cup confectioner's sugar a 1/4 cup at a time until combined. Once all the confectioner's sugar has been combined, whisk on high speed for a minute or so, until the filling is thick and smooth. Add 3 drops red food coloring, and continue whisking until the frosting is a pale pink. Use immediately.
Use a mini offset spatula to frost the top of each cookie; sprinkle immediately with nonpareil sprinkles.

Get the Recipe: Chocolate Sugar Cookies with Pink Frosting