Preheat your oven to 350°F and line a baking sheet with parchment paper. While the oven heats, sift the powdered sugar into a bowl to remove any lumps—this ensures a smooth, lump-free frosting later. Measure out the sanding sugar into a shallow bowl for coating. Have all your ingredients measured and ready before you begin mixing the dough.

In a medium bowl, combine the strawberry cake mix, eggs, and vegetable oil. Mix until the dough comes together—it should be thick and slightly sticky. The cake mix already contains leavening agents, so you don't need to worry about activating them; just mix until fully incorporated, which takes about 1-2 minutes of stirring.

Using a spoon or small cookie scoop, portion the dough into 1-inch balls. Roll each ball in the sanding sugar until fully coated—I like to press the ball gently into the sugar so it adheres well and creates that sparkly, shimmering exterior. Place the coated balls on the prepared baking sheet, spacing them about 3 inches apart to allow room for slight spreading.

Bake for 7-9 minutes, until the edges are set but the centers still look slightly underbaked—they will continue to cook slightly as they cool. The cookies should be soft and chewy, not crispy. Remove from the oven and let them cool on the baking sheet for 2-3 minutes, then transfer to a wire rack to cool completely before filling.

While the cookies cool, make the frosting. In a large bowl, beat the butter with the salt, vanilla, almond extract, and heavy cream on medium speed until smooth and fluffy, about 2-3 minutes. Gradually add the sifted powdered sugar from Step 1 in portions, beating well after each addition. I like to add the lemon zest at the end—it brightens the strawberry flavor beautifully without making the frosting taste overly citrusy. Once all the sugar is incorporated, whip on high speed for another 2 minutes until light and fluffy.

Once the cookies are completely cooled, spoon or pipe about 1-2 tablespoons of frosting from Step 5 onto the flat bottom side of one cookie. Press a second cookie gently on top, flat-side down, creating a sandwich. The frosting should peek out slightly around the edges for a pretty presentation. Serve immediately or store in an airtight container for up to 3 days.