Grease 12 microwave-safe mugs. Whisk together the flour, baking powder and salt, and set aside.
In a large bowl, whisk together the milk, sugar, eggs, oil and vanilla until well blended; stir in the flour mixture until smooth. Stir in the food coloring, and fold in the chopped TWIX® Cookies & Creme.
Scoop 1/4 cup of batter into each mug. One at a time, microwave on High for 1 to 1 1/2 minutes or until puffed and tester inserted in the center of the cake comes out clean.
Allow to stand for 1 to 2 minutes or until slightly cooled before serving.
Tip: Top cakes with a dusting of icing sugar, dollop of whipped cream or scoop of vanilla ice cream if desired.