To prepare a vegan vanilla cake with cookies n cream frosting recipe, first you will need to prepare the cake batter. First, mix the flour, baking powder, sugar, cocoa, vanilla, and salt together. Then, add the wet ingredients to the dry ingredients and mix until the ingredients are well combined. Next, pour the batter into the greased and floured cake pan and bake for 35 to 40 minutes, or until toothpick inserted in the center comes out clean. Remove the cakes from the oven and allow them to cool for 10 minutes before frosting.