These Chocolate Sandwich Cookies are soft, chewy, and totally irresistible! Get the easy recipe and find out to make the best chocolate sandwich cookies with cake mix and vanilla frosting. Rich and creamy vanilla filled chocolate cookies are sure to be a hit with family and friends.
Preheat oven to 350 and line a baking sheet with parchment paper. Set aside.
In a mixing bowl, combine cake mix, eggs, vegetable oil, and vanilla. Use a hand mixer to beat for 1 minute. Mixture will be thick and your mixer may struggle, but it should come together fine.
Pour batter into a gallon size resealable plastic bag and seal shut. Cut a corner of the bag to about 1/2" opening.
Pipe batter onto baking sheet in 2 to 2-1/2" circles, keeping them 2" apart. Bake for 8 minutes. Remove from oven, let cool on pan for 2 minutes before removing the pan and cooling completely on a cooling rack.
Once cookies are cool, pair the same size cookies together. Spread frosting onto one cookie and gently press another cookie on top. Repeat until all cookies are filled.
Store cookies, with wax paper between layers, loosely covered.