Preheat oven to 325°. Grease an 8x8-inch metal cake pan or line with parchment paper.

In a saucepan, melt butter over medium heat. Stir frequently as it continues to bubble. Remove from heat when small brown specks appear and it smells like nutty caramel.

Add sugar, cocoa powder, and salt to combine.

In separate bowl, beat eggs. Once butter mixture has cooled in pot 4-5 minutes, slowly pour eggs into saucepan, stirring constantly until well combined.

Add vanilla and beet puree; stir to combine.

Add flour and baking powder; stir to combine.

Add chocolate chunks; stir to combine.

Bake 25–35 minutes in preheated oven or until top no longer looks wet.