Preheat oven to 350 degrees Fahrenheit.
In a mixing bowl, combine peanut butter, margarine, sugars, cornstarch, applesauce, vanilla, and lemon juice until well-incorporated.
Add flour, oats, baking powder, and salt to mixing bowl. Stir to combine.
Add almond milk one tablespoon at a time until cookie dough is soft, sticks to itself, and is easy to handle.
Roll dough into 2-tablespoon-sized balls and place on lined cookie sheet.
Use a fork to make characteristic peanut butter cookie stamp on each cookie, being careful not to push too hard and form cracks around the edges.
Bake cookies for about 10-11 minutes at 350 degrees. Allow cookies to cool for 5 minutes on the cookie sheet before attempting to move them to a cooling rack.