Melt 1/2 cup of butter or margarine on the stove or in the microwave. Use a pot or bowl that is large enough to allow you to mix the remaining ingredients in (saving on dishes!).
Mix the sugar or sugar and molasses into the hot butter or margarine.
Add the rolled oats and baking powder to the top of the sugar/oil and then stir until the whole lot is evenly mixed.
Pat into an 8″ x 8″ baking pan (I prefer silicon) and bake for 20 minutes in the preheated oven
Allow to cool for about 5 minutes and then slice the bars to the desired size. The mixture will still be friable at this point but will harden as it cools.
Allow the bars to cool for about 30 minutes more and then they are ready to be enjoyed.