4 Ways to Make Dr. Pepper - wikiHow Copycat Diet Dr Pepper 1 Combine the cola stevia and cherry flavoring in a 12 fl oz (350 mL) glass. Use the dropper that comes with the cola stevia bottle to add 40 drops. Grab a teaspoon to add the 1.5 tsp (7.4 mL) of natural cherry flavoring. Mix them well with a spoon or stirring rod to blend the flavors. [7]