Homemade Sweetened Condensed Milk

This should be made as you use it - the milk doesn't store well. One recipe equals one can of store bought sweetened condensed milk.
Prep Time: 10 minutes
Ingredients:
1 cup nonfat dry milk powder
2/3 cup sugar
1/3 cup boiling water
3 Tbsp. butter
Preparation:Combine all ingredients in a small bowl and beat well with wire whisk until smooth.
Use in place of canned sweetened condensed milk in recipes.