Weekly baking - Chocolate button tray bake

I like to bake & cook. I am the main person to prepare our food. My husband can cook too but he always over do it. He doesn't for some reason have inner "measurement". Unfortunately his portions are very off (a lots of food for 2 portions but not enough for 4 so we can have it next day). Also he likes to add staff to the food so then very easy receipt is quite complicated and expensive. Easy pasta bake can cost twice much than if I will be cooking it.
But sometimes I make a mistake of buying wrong ingredients. Yesterday I have been baking marbled trey bake and I didn't have cocoa powder for marbled effect! I have bought chocolate buttons instead of cocoa. No idea how I have managed it. So sometimes baking & cooking is about improvising. I have just put chocolate buttons on top of cake mix a voila! Chocolate button tray bake. It was delicious!

Our baking and cooking is not only about eating healthy but also about cost. What is the point of "slaving" in the kitchen when there is no difference between my cake and supermarket bought. I am trying to know when to fight my battles. I know that lemon tart on offer in supper market is cheaper than any of mine baked so when we have really taste for it I will buy it ( it isn't very often).
I always try to put more than I food in one time into the hot oven to "save"money on heating it.

 It isn't much but over a year it will add up.
With tray bake I have been baking homemade lasagna. All ingredients bought on offer or in Aldi and cost was under £7 for it ( £1.75  per portion) and we had it for lunch next day too.