Preheat the oven to 350°F (175°C). Line a 9×9-inch pan with parchment for easy removal. Yes, parchment is your friend here.

In a bowl, whisk eggs, maple syrup, melted oil, and vanilla until smooth. Don’t overthink it—just give it a quick whisk and move on.

In another bowl, combine coconut flour, cinnamon, baking soda, and salt. Stir to break up any clumps like you’re a polite kitchen soil scientist.

Pour the wet mix into the dry mix. Add the grated apple and optional mix-ins. Stir until just combined. The batter will be a bit thick—that’s coconut flour doing its thing.

Spread evenly in the prepared pan. Smooth the top with a spatula so the bars bake evenly and don’t resemble a bumpy moon.

Bake for 22–28 minutes, or until the edges are golden and a toothpick comes out clean or with a few moist crumbs. Let cool completely before cutting for clean bars.