Chocolate Caramel Bars

This is one of the old recipes that I used to make when my family was young (and I had lots of help eating it!). Now I'd have to say that it makes an awful lot and we just don't eat like we used to!

14 oz (400 gm) or about 64 individually wrapped caramels
1 cup (250 ml) evaporated milk
2 cups (500 ml) all purpose flour
2 cups (500 ml) oats
1 1/2 cups (375 ml) lightly packed brown sugar
1 tsp (5 ml) baking soda
1/2 tsp (2 ml) salt
1 1/2 cups (375 ml) butter or margarine, softened
2 cups or 1 pkg (300 g) semi-sweet chocolate chips
1 cup (250 ml) walnuts, chopped

Melt caramels and evaporated milk  on low heat, stirring until smooth.
Combine flour, oats, brown sugar, baking soda, and salt in large mixing bowl.
Cut in butter until mixture is crumbly.
Press half of mixture into 15" x 10" pan or 2 9" square pans.
Bake at 350 F (180 C) for 5 minutes.
Sprinkle chocolate chips and walnuts evenly over baked crust.
Pour caramel mixture on top.
Sprinkle with the remaining crumb mixture.
Bake 15- 20 minutes longer or until golden.
cool and cut into bars