In a large bowl, beat your butter on high speed until smooth and creamy. Add in your sugar and beat on high speed until well combined. Add in your oil, eggs, and vanilla and beat until combined.
Pour half of your batter into the prepared bundt pan, then evenly place your oreos in the pan on top of your batter, top with remaining batter. Bake for 50-55 minutes or until a toothpick inserted into the centre comes out almost clean.