Try baking and cooking foods you have positive memories with... think foods from your early childhood like holiday sugar cookies, comfort foods and family recipes. For me, Pillsbury cookies always do the trick for my mom and I – while they may not be gourmet, they sure are nostalgic for the both of us. The key here is that you want the food to be from something you haven't made in a long time. If what you make comes from a memory made between the ages of 11 and 25, it becomes less likely to evoke nostalgia than something from when you were between 6 and 10 as scent and taste-based memories are more likely to reach their peak (and ability to leave a mark) at this stage of life. The tricky part is trying to remember what foods you used to eat.