Preheat oven to 350°F. In a large mixing bowl beat butter and sugars. Add egg and vanilla and beat until light and fluffy.
In a separate mixing bowl, combine dry ingredients with graham cracker crumbs; add to butter mixture and mix until well combined.
Divide dough in half and press one half into a greased 9x13 baking dish.
Place 3 chocolate bars over the dough, laying them side by side, then cut the remaining chocolate bar into 4 lengthwise strips. Place these chocolate strips into the open areas around edges of the whole chocolate bars already in the baking dish.