It took several experiments such as the one illustrated below before I arrived at a suitable combination of ingredients. This recipe makes 9 fl oz — enough for two 4 1/2 oz shakes.
(measurements by weight)
4 oz Philadelphia Cream Cheese Spread
2 oz heavy cream
3 oz unsweetened vanilla almond milk
3 pinches stevia
3 drops of LorAnn's Cookies & Cream
The best price I've found for Philadelphia Cream Cheese Spread is at CostCo where they sell it in 48 oz tubs. Be sure to buy Philadelphia Cream Cheese and that it says Spread on the tub.
See Resources for more information on stevia.
Mix the above ingredients with a stick blender, pour into two small glasses, and refrigerate for 12 hours before consuming. Keeps well for several days.
The following summarizes the carbohydrate and fat content of a 4 1/2 fl oz milk shake (half recipe) in grams.
Ingredient sfa pufa mufa tfa Carbs Protein cream cheese spread 10 1 5 16 2 4 heavy cream 6 0 3 9 0 0 almond milk 0 0 0 0 0 0 Total 16 1 8 25 2 4
sfa (saturated fat), mufa (monounsaturated fat), pufa (polyunsaturated fat), tfa (total fat)