Caramel Mallow Bars

2/3 cup butter, softened (10 2/3 tablespoons)
1/2 cup packed light brown sugar
1 1/2 cups flour
1/2 cup finely chopped pecans
1/2 cup graham cracker crumbs
28 caramels
2 tablespoons water
1 cup miniature marshmallows
1/2 cup semisweet chocolate chunks

Heat oven to 350 degrees F.

Cream the butter and brown sugar together until light and fluffy. Add the flour, pecans, and graham cracker crumbs; mix well. Reserve 1/4 cup of the mixture; press remaining mixture into the bottom of a greased 9-inch square baking pan.

Bake for 18 minutes.

Meanwhile, melt the caramels and water together in a heavy saucepan over low heat, stirring often, until smooth; pour over the crust. Sprinkle with the reserved crumb mixture, marshmallows, and chocolate chunks.

Bake for 12-14 minutes more, or until the marshmallows are lightly browned.

Cool on a wire rack before cutting into squares.