• Preheat the oven to 350°F. Line a large baking sheet with parchment paper.
• In a large bowl, add cake mix, water, cocoa powder, oil, food coloring, eggs, and vanilla. Using a hand mixer on low speed, mix until just moistened, scraping sides of bowl frequently.
• Increase the speed to medium. Mix for 2 more minutes.
• Spoon 2 tablespoons of batter onto the lined baking sheet, leaving about 2 inches between each tablespoon. (The cakes will spread as they bake.)
• Bake for 8 minutes, turning the baking sheet halfway through baking. The whoopie pies are done when they are puffed and spring back when touched. Let the cookies cool on the baking sheets for 1 minute. Then, transfer to wire racks to cool completely.

Orange Buttercream

• In the bowl of a stand mixer with the whisk attachment, add butter. Whisk on medium-high speed until light and fluffy (about 3 minutes).
• Add vanilla and almond extract.
• With the mixer on low, slowly add confectioners' sugar, milk, and salt, frequently scraping down the sides and bottom of the bowl.
• Remove the bowl from the stand mixer. Fold in the food coloring.

Assembly

• To assemble the Whoopie Pies, place 1 tablespoon of buttercream on the flat side of one cookie. Top with a second cookie, pressing gently to spread the filling. Repeat with remaining cookies and buttercream.
• Store whoopie pies in the refrigerator for up to a week.