1/3 cup butter
1 cup packed light brown sugar
1 teaspoon cinnamon
3 tablespoons cornstarch
1/4 teaspoon salt
1/2 cup brown sugar for pastry
Preheat oven to 350 degrees F (175 degrees C).
In a large bowl, cream together butter, brown sugar and cinnamon. Beat in cornstarch and salt. Mix in brown sugar for pastry. Spread onto a large baking sheet.
Bake in preheated oven for 1 hour, or until a toothpick inserted into the center of the cake comes out clean.