Oil and liberally flour a bundt cake pan or any cake pan you are using. Preheat the oven to 350 degrees Fahrenheit/180 degrees Celsius.
Place the flour in a bowl along with the baking soda, baking powder, cinnamon, corn starch and salt. Whisk to mix all ingredients.
Add the wet ingredients: sugar, non-dairy milk, oil and pure vanilla extract. Mix with a spatula. Scrape the sides and bottom to make sure there is no dry flour in the bowl. The batter will be stiff.
Add the finely chopped apples to the batter and mix them in. Set the batter aside for 15 minutes. This will give the apples some time to express moisture into the batter.
Stir the chopped nuts, if using, into the batter. Scoop the prepared batter into an oiled and floured bundt cake pan or another cake pan. Smooth the top.
Bake in a preheated 350-degree Fahrenheit/180-degree Celsius oven for 45 minutes or until a toothpick inserted near the center comes out clean. Let the cake cool on a rack for 15 minutes, then invert it onto a plate. To do this, place the plate over the bundt pan and flip it quickly. Continue to cool on the rack.