For the crust, Melt butter. Stir flour and sugar together and add the melted butter. Pat into a 9x9 baking dish. Bake at 350 F for 20 minutes.
For the caramel, Boil ingredients over medium heat for 5 minutes; stirring constantly. Remove from heat and beat until thick. Pour mixture over crust. Cool.
For the chocolate, melt chocolate chips and spread evenly over caramel layer. Cool. Cut into bars.
[My 2 Cents]
The recipe says to cool the caramel mixture before adding the chocolate layer. I found the last time I made these that since I let the caramel cool before adding the chocolate, once the chocolate was hardened it separated when I cut them into bars. I think if you add the chocolate while the caramel is still warm it will "fuze" together better and allow for the bars to stay in tact when cutting.
Adapted from My friend, Kirsche