Hi there! If you are on this page, then you are one of the kind souls who is interested in baking for someone with a nut allergy, though you do not personally deal with severe food allergies in your own home.
Before you get out that mixing bowl, though, consider if it's a good idea to offer to bake something "nut-free" for someone with a life-threatening allergy. Most parents of kids with severe allergies have strict rules about what kids can eat, and that's because avoiding the allergen is the best way to remain healthy, stay out of the ER and all the rest.
While many of us may eventually trust some close friends and family members to learn to bake nut-free, what many people don't understand is that nut-free baking is more than the ingredients you use and wiping down your kitchen. That's why, for many of us dealing with severe allergies, that circle of trusted bakers is very small -- and generally does not include a casual acquaintance, i.e. classmate.
Baking is a crucial skill when you are dealing with allergies and most bakeries can't offer safe products for allergic people -- that's why I have a lot of recipes on this blog. It's important to point out that when you deal with a life-threatening nut allergy, baking takes on some serious risks that many people don't consider when they offer to bring a homemade treat that is "nut-free." Don't worry--most people don't think about this stuff unless they have to, i.e., they've witnessed their child experiencing a severe reaction.
Trace amounts of food allergens may be invisible but believe it or not, what you can't see can cause a severe, life-threatening reaction. Cleaning your kitchen of allergens is great but, allergens can be present on pretty much anything and you wouldn't necessarily know it. A few examples: kitchen sponges, dish towels, baking pans, the inside of your oven, etc. If you use peanut/nut products a lot, it is likely they are simply in the environment.
As much as I know about food allergies, I would never offer to bake, say, "dairy-free," for a classroom or casual acquaintance because I use milk, butter, etc. so frequently in my kitchen. So that means, trace amounts of dairy may be present in my food just because I use it so regularly in my baking and cooking. The same goes for you if you and your family are using Nutella, peanut butter, cashews, almonds, mixed nuts, granola, Chinese or Thai foods, etc.; there is a good chance of introducing nut allergens into anything you bake.
As a parent, I always appreciate it when families choose store bought foods with a label for class parties or better yet -- no food at all. In elementary school we stuck to some simple rules: My child did not eat anything homemade from an outside kitchen and that was because if we didn't know how/where something is produced, she simply could not safely eat it. Nothing personal, just a health and safety rule that has served us very well over the years.
For family gatherings, talk to your family members and find out what they will feel comfortable serving to those with allergies. That way, you can save yourself some time and misunderstandings.
For more about why it's not a good idea to bake nut-free if you don't have a "nut-free" kitchen, click this link for a post that explains the risks.
Thank you for your concern about baking nut-free. Remember, though my recipes are all nut-free, I can't guarantee the safety of any of my recipes if they are NOT made in a nut-free kitchen or by people not used to dealing with allergies.