Make a well in the center of the dry ingredients and pour in the wet ingredients. Mix until just combined and no dry flour is left.
Add half the diced apples to the batter and fold into the batter to distribute.
Spread the batter into the lined baking pan. Gently drop the pan on the counter a few times to remove any large air bubbles. Distribute the remaining apples on top, gently pressing them into the top of the batter.
Mix together cinnamon sugar and sprinkle over the apples.
1 tbsp granulated sugar, ½ tsp ground cinnamon
Bake: Place on the middle rack of your oven and bake for 45-60 minutes, until the top is firm and a toothpick inserted in the center comes out clean or with a few moist crumbs (but no wet batter). Tent the pan with foil if the apples on top start to burn.
Glaze: Place the baking pan on a wire rack. Mix together the glaze and drizzle over the cake while still warm. You can add more milk to the glaze if you want it thinner.
80 grams (⅔ cup) powdered sugar, 1 tbsp soy milk
Cool: Let the cake cool in the pan for 10 minutes, then use the sides of the parchment paper to carefully remove the cake from the pan. Place the cake on the wire rack to cool completely.
Store: Store leftovers covered in the fridge for up to 5 days. You can also cut into individual slices and freeze for up to 3 months.