Toffee Bars

1 cup butter
1 cup brown sugar
1 cup white rice flour
1 cup sweet sorghum flour
1 egg yolk
1 teaspoon vanilla
1/4 teaspoon salt
1 cup Hershey’s milk chocolate chips

Cream butter and brown sugar. Add egg yolk and vanilla and mix well. Add flour and salt and mix until moist. Put into a greased 9-inch x 13-inch pan and bake for 20 minutes at 350 degrees F. When you pull it out of the oven, sprinkle chocolate chips over it and spread.