Vanilla Cream Sauce

Here is the recipe for Vanilla Cream Sauce to go with the rhubarb crumble:
2 cups whipping cream
2/3 cup sugar
4 Tbs. all-purpose flour
3 Tbs. butter
1 tsp. vanilla extract
Stir first 3 ingredients together in a medium saucepan. Cut butter into slivers and add. Cook, stirring constantly, over medium heat until butter is melted and mixture begins to boil and/or is thickened. Remove from heat, and stir in vanilla. Serve warm.
For a thinner sauce use only 2 Tbs. of flour. For a thicker sauce use 5 Tbs.
-------------------------------
This sauce would be good used a variety of ways, but be forewarned, it is very rich! It is simple to make, but tastes quite luxurious. (I found this recipe online, though I've forgotten where.  For a change, I don't think I altered this recipe. Ha.)