My go to flavor is vanilla when it comes to making cookies and cream cake in a jar. Add a bit of extra flavor by mixing in an Oreo pudding mix to the batter, or even adding crushed cookie crumbs. However, this Oreo cake can also be made with a classic chocolate cake. The rich chocolate flavor pairs perfectly with the vanilla buttercream, creating a decadent treat that’s sure to please. You can also mix it up by using different flavors of cake or even adding chocolate chips or Oreos to give your cake an extra boost of sweetness.