At the Mormon Mommy they have posted a recipe for a chocolate milkshake that they say tastes just like a Wendy' frosty. I haven't tried it yet- but several people commented that it really did meet and pass their family taste test- here is what she said:
If you follow these directions, I kid you not, you will end up with a chocolate milkshake so much like a Wendy’s frosty you will be amazed. I beleive the original credit for the recipe goes to the Prairie Homemaker website, but I’m not 100% on that one.
1 1/2 - 2 cups ICE water- really, really cold.
1 1/2 cups non-fat dry milk powder
2/3 cup sugar
1/4 cup unsweetened cocoa
2-3 cups ice cubes
2 Tbsp vegetable oil (yes, really- it’s an emulsifier)
Place ALL the ingredients in the blender, including the oil. Use less water for a thicker milkshake or more for a shake that’s easier on your blender motor. With lid on, process for two minutes. Makes about 4 shakes.