01 -
Follow the instructions on the cake mix box to prepare the batter. After mixing the batter, fold in about 5 chopped Oreos (half of the amount set aside for the cake).
02 -
Pour the batter into the prepared pan(s) and bake according to the box instructions. Allow the cake to cool completely for at least 30 minutes before assembling.
03 -
In a large mixing bowl, combine the room temperature butter and vegetable shortening. Mix until smooth and well incorporated.
04 -
Add one cup of powdered sugar and the vanilla extract to the butter mixture. Mix until fully combined, starting with a low speed then increasing to medium speed.
05 -
Add the remaining two cups of powdered sugar, 2 tablespoons of milk (or coffee creamer), and both gel food colorings. Mix starting on low speed and increase gradually to high. Beat for 2-3 minutes.
06 -
Test the silkiness of the frosting with a spoon. If it's not smooth enough, add one more tablespoon of milk, then beat on medium-high for 4-5 more minutes to create a fluffy, easy-to-pipe frosting.
07 -
Add the blue frosting to a piping bag fitted with tip 1M or your preferred piping tip. Have your mason jars, chopped cookies, cake, and decorations ready for assembly.
08 -
Add 1-2 scoops of crumbled cake into each mason jar. Use the back of the scoop to gently press it down to create a compact layer.
09 -
Pipe frosting directly on top of the cake layer. Top with a sprinkle of chopped chocolate chip cookies and chopped Oreo cookies.
10 -
Add another scoop of cake, followed by frosting, then cookies. Repeat once more if there is space in the jar. End with a decorative swirl of blue frosting on top.
11 -
Press two candy eyeballs into the top frosting layer. Add half of a chocolate chip cookie (positioned as the mouth) below the eyes to create Cookie Monster's face.
12 -
For a finishing touch, wrap blue ribbon around the rim of each jar, securing it with glue dots.