Preheat your oven to 350°F (175°C) and grease an 8-inch round baking pan with parchment paper.

Boil the chopped beetroots until tender (30-40 minutes), then puree until smooth.

In one bowl, whisk together flour, cocoa powder, baking powder, and salt.

In another bowl, mix sugar, vegetable oil, eggs, and vanilla until creamy. Stir in the beetroot puree.

Gradually add the dry ingredients into the wet mixture until just combined; do not overmix.

Pour the batter into the prepared pan and bake for 30-35 minutes or until a toothpick comes out clean. Let cool completely before serving.