Tried & True: Jam Bars

I've had this recipe as a quick go-to dessert staple for years. I believe it came from my mother's aunt, Ardis Rigby.

3/4 cup margarine
1 cup brown sugar
A splash of vanilla
1 1/2 cup flour
1 1/2 cup oatmeal
1/2 teaspoon salt
1/2 teaspoon baking soda
Jam

Cream together the margarine, brown sugar, and vanilla. Then add the flour, oatmeal, salt, and soda; mix until crumbly.
Divide mixture in half. Press one half of the mixture into the bottom of a 9x13 inch pan. Cover with a layer of jam (I usually use strawberry or a mix of strawberry and something else). Sprinkle the remaining crumbled mixture on top of the jam layer. Pat down lightly.
Bake in a 400 F oven until lightly golden (approx. 15-20 minutes).
Cool in pan.
If desired drizzle a glaze over the top. I use a combination of milk, powdered sugar, and vanilla for my glaze.
Once completely cool, cut into squares and enjoy. For easier removal, cut away the edges first.