1-2-3 biscuits. cream 1oz (yes, I'm old) of sugar and 2oz of butter in a bowl. Mix in 3 oz of plain flour. (or 50g, 100g, 150g). Add a little gorund ginger or cocoa for flavour if you'd like. Roll out on a floured surface, and cut out biscuits. Cook 10 mins at 180 deg C. Can be iced if required.
Mine also like making banana cake. Get them to slice a banana into the bottom of a cake tin (those silicon ones work well for this). Pour over some posh toffee sauce. The add a cake made from 4oz (100g) marg, 4oz (100g) sugar, 2 eggs and 4oz (100g) of SR flour. Cook in oven, and allow to cool. They love cutting things.
My lo likes cutting, so I usually let her loose on mushrooms, which now go in everything as then she feels like she's.contributed to the meal. Also cutting spring onions into a dish with scissors. Little.things that make her feel involved, preparing the herbs adding pepper etc.