Preheat the oven to 350°F (175°C). Lightly grease an 8- or 9-inch round cake pan and line the bottom with parchment paper; grease the parchment as well. Alternatively, use a springform pan.

Dry ingredients

In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, almond flour, baking powder, baking soda, and fine salt until evenly combined and free of lumps.

Wet ingredients

In a separate bowl or large measuring cup, whisk the unsweetened applesauce, plant milk, oil, vanilla extract, and apple cider vinegar until smooth. The vinegar will react with the baking soda to help the cake rise.

Combine batter

Make a well in the center of the dry ingredients and pour in the wet mixture. Gently fold with a spatula or whisk just until no large streaks of flour remain. Do not overmix; a few small lumps are fine. Scrape the bowl to ensure everything is incorporated.

Transfer to pan and top

Pour the batter into the prepared pan and smooth the top with a spatula. Sprinkle the sliced almonds evenly over the batter and press lightly so they adhere. If using, drizzle the 1 tablespoon of maple syrup lightly over the top for extra sheen.

Bake

Bake in the preheated oven for 30–40 minutes, or until the top is golden and a toothpick inserted into the center comes out clean or with a few moist crumbs (not wet batter). Rotate the pan halfway through if your oven has hot spots.

Cool

Remove the cake from the oven and let it cool in the pan on a wire rack for 10–15 minutes. Run a knife around the edge, then invert onto the rack to remove the cake from the pan (or release the springform). Let cool completely, about another 30–45 minutes, before finishing.

Finish & Serve

Optional glaze

If using the optional maple glaze, gently warm the remaining 1 tablespoon maple syrup and brush it over the slightly warm cake to add shine and moisture. Allow it to set for 5–10 minutes.

Dust and slice

Just before serving, dust the top lightly with powdered sugar or powdered coconut sugar. Slice into 8–10 pieces and serve at room temperature. The cake keeps well covered at room temperature for 2 days or refrigerated for up to 5 days. Bring to room temperature before serving if chilled.