Preheat the oven to 375F.
In a thick-bottomed pan, mix all the ingredients for the caramel filling until the sugar dissolves. Set over medium heat and bring to the boil.
Cook, stirring constantly, until thickened (takes about ten minutes). Set aside.
Make the crust and topping.
In a mixing bowl, cream the butter and sugar.
Add the flour, baking powder and coffee granules. Mix until blended. The mixture will have the appearance of pea-sized crumbs.
Take two thirds of the mixture and press onto the bottom of a 7" x 11" pan.
Pour the caramel filling over the crust.
Level off the caramel with the back of a spoon or an offset spatula.
Sprinkle the remaining third of the crumbs over the caramel.
Tilt the pan to distribute the crumbs evenly so that the entire surface is covered.
Bake for 20 to 25 minutes.
Cool in the pan for about 40 minutes. Cut into squares while still warm.