Chocolate Filled Walnut-Oatmeal Bars

Description
Makes about 4 dozen bars.

Ingredients

 * 1 cup (2 sticks) butter or margarine, softened
 * 2 cups packed light brown sugar
 * 2 eggs
 * 1 tsp vanilla extract
 * ½ tsp powdered instant coffee (optional)
 * 3 cups quick-cooking rolled oats
 * 2½ cups all-purpose flour
 * 1 tsp baking soda
 * ½ tsp salt
 * 1½ cups chopped walnuts, divided

Chocolate filling

 * ½ cup (1 stick) butter or margarine
 * ⅔ cup Hershey's cocoa
 * ¼ cup sugar
 * 1 can (14 oz) sweetened condensed milk (not evaporated milk)
 * 1½ tsp vanilla extract

Directions

 * 1) Heat oven to 350°F.
 * 2) Beat butter and brown sugar in large bowl until well blended.
 * 3) Add eggs, vanilla and instant coffee, if desired; beat until fluffy.
 * 4) Stir together oats, flour, baking soda, salt and 1 cup walnuts; gradually stir into butter mixture with spoon.
 * 5) Set aside 2 cups dough.
 * 6) Press remaining dough evenly onto bottom of ungreased 15½x10½x1-inch jelly roll pan.
 * 7) Prepare chocolate filling; spread evenly over dough.
 * 8) Crumble reserved dough evenly over filling.
 * 9) Sprinkle with remaining ½ cup walnuts.
 * 10) Bake 25 minutes or until top is golden brown (chocolate will be soft).
 * 11) Cool completely in pan on wire rack; cut into bars.

Chocolate filling

 * 1) Melt butter in medium saucepan over low heat.
 * 2) Stir in cocoa and sugar.
 * 3) Add sweetened condensed milk; cook, stirring constantly, until smooth and thick.
 * 4) Remove from heat.
 * 5) Stir in vanilla.