I got this recipe from The Hillbilly Housewife. It's a really good alternative to using ice cream and it really does taste like a Wendy's frosty!
1-1/2 to 2 cups ice water
1-1/2 cups nonfat dry milk powder
2/3 cup sugar
1/4 cup unsweetened cocoa
1 teaspoon vanilla
1 to 1-1/2 trays of ice cubes, as much as you can spare
2 tablespoons corn oil plus a 5-second squirt of non-stick spray for emulsification purposes
Place all of the ingredients into the blender, including the oil and the non-stick spray. Use less water for thicker milk shakes and more water for shakes that are easy on your blender motor. The blender should be about 3/4's full. Place the lid on. Process for a full 2 minutes. Pour into cups and serve. Makes 4 - 12oz servings.
I love this recipe because it makes very rich milk shakes without any ice cream. I don't always have ice cream in the house because the kids eat it so fast. With this recipe we can have delicious frosty milk shakes for a fraction of the cost of those using ice cream. And all the ingredients are on the pantry shelf.