All About Baking
You'll typically be able to find baked goods to white/green your needs with at lots you visit. The reason for that is that they fill up energy, comfort, and hunger very quickly, and most baked goods don't spoil (unlike salads and regular hc), so they are the most popular item that hosts and roommates prepare for their guests.
In order to bake, you will first need to have one set of eggs and three sets of butter in your inventory. Eggs come from chickens, and butter is churned using a butter churn (which will drain your energy and comfort pretty fast). Both items can be bought from other sims/stores for around $2,000-3,500, depending on the store. You'll also need an oven for bakers, which looks like this:
And each time you bake, it will cost you $100.
An important thing to note is that when you bake, you have a chance to bake one of nine items. Some of these items do spoil, so if you happen to bake one of them, be sure to serve that one for your guests before the ones that don't. Otherwise, your ingredients and efforts will spoil. Here is a table with everything you can bake:
As you can see, you do have a higher chance to bake non-perishable items, but the downside is that they have fewer servings than the perishable ones.
Have fun baking!