Start by preheating your oven to 375°F so it's ready once your batter is mixed. While it heats, chop one cup of peaches and slice the rest separately, since you'll use them differently in the recipe. I like to leave the skin on for extra color and a softer texture.
In a large bowl, stir together the oats, almond milk, cinnamon, vanilla, almond extract, maple syrup, coconut oil, sea salt, and the chopped peaches. Mix until everything is evenly combined and no dry oats remain at the bottom of the bowl.
Coat your 8x8 baking dish with non-stick spray, then pour in the oat mixture. Arrange the sliced peaches over the top in whatever pattern makes you happy. This step decides how pretty the finished dish looks, so take your time with it.
Slide the dish into the oven and bake for 45-50 minutes, until the top turns golden and the center is set. Let it rest for about 5 minutes once it's out, since it firms up a bit as it cools.
Scoop it into bowls while it's still warm, or portion it into containers for the week ahead. I usually add a splash of milk on top right before eating to loosen it up a little.