• Butter: Margarine or olive oil are the best choices. For margarine, Annie recommends Earth Balance brand for the most "buttery" flavor, but any vegan brand can be substituted directly for butter. Don't try to brown it in recipes calling for browned butter, though.
Baking with olive oil also works well. (Use 1/4 cup plus 2 tablespoons olive oil for every cup of butter.) It can be used to grease pans as well, as long as the coating is very light. Annie notes that olive oil is a great choice for vegans worried about the deforestation and orangutan hunting associated with the palm oil industry, and that Earth Balance gets 70% of their palm oil from farms that are part of the RSPO and the rest from Brazil, where deforestation is still an issue, but where there are no orangutans.
• Buttermilk: Mix 1 cup soymilk with 1 teaspoon apple cider vinegar or lemon juice and let the mixture sit until it separates.
• Condensed Milk: Canned coconut milk is the best substitute.
• Eggs: Egg substitutions depend on the type of recipe you are making. For egg whites in recipes like lemon bars, use agar agar powder mixed with water according to the package directions. To replace whole eggs in chewy baked goods like brownies, use one ripe mashed banana for every egg the recipe calls for. As a general rule, one tablespoon applesauce can replace one egg in most baking recipes.
• Heavy Cream: Put a can of coconut milk in the fridge for 48 hours. Open it up and use just the solidified top layer in place of heavy cream.
• Honey: Use an equal amount of maple syrup or agave in place of honey.
• Milk: Among the non-dairy substitutes for milk, Annie recommends soymilk because it is a bit thicker than almond or rice milk. When using a thinner non-dairy milk, use a little less than the amount of milk called for in the recipe.
• Sugar: While there is often concern over the use of bone char in sugar processing, only about half of the sugar in the US is processed this way, so there are several vegan sugar options. Look for beet sugar or unbleached sugar — which may even be labeled "vegan sugar" — or check out this list of sugar brands that do not use bone char.
For more of Annie's vegan baking tips and recipes, check out her blog Meet the Shannons and watch for her upcoming book Betty Goes Vegan: Over 500 Classic Recipes for the Modern Family.
Do you have any tips for vegan baking substitutions?