Basic bar cookie

This is my favourite cookie recipe. The base is almost like a chocolate chip cookie but sort of toffee-ish, with all brown sugar and no white, and then you add a couple of cups of whatever strikes your fancy (just one, or a mixture of items: pecans, shredded coconut, chocolate chips, raisins, finely shredded carrots, etc). Half the fun of these is thinking of new things to put into them.

With electric mixer, beat 2 eggs, 1 cup sunflower margarine/spread, 1.5 cups brown sugar, 1/2 tsp baking soda, and 1 tsp vanilla. Mix about 2 minutes on medium, then stir in 2 cups of your favourite GF flour mix (Doves Farms for me, as always). Lastly, stir in a total of 2 cups of one or more additions (above).

Spread into an oblong pan and bake at about 325 (gas mark 3) until a knife comes out clean. Be careful not to over-bake. Cut into squares and try not to eat too many. (Difficult!)

EDIT: Variation on this cookie