Preheat oven to 350 F. Gently cut the tops of the tomatoes off and scoop out the insides with a small spoon or melon baller. Flip tomatoes upside down on a paper towel for a few minutes to drain some of the juice out. Once drained, gently rub olive oil on both the outside and inside of the tomatoes. Place upside down on a baking sheet lined with parchment paper and bake for 5 minutes. Set aside.