I don't agree with "don't bake any cakes for whatever reason". I think if it gives you joy to do so, bake. If it doesn't, don't. I wouldn't give any other explanation than a choice of: - "I don't feel like baking these days." - "I can't commit to doing this." - "No, I can't." Then, because you really don't owe them an explanation, when they ask "Why not?" you might just raise your eyebrows, and say in your most offended tone "Ex-cuuuu-se me?"