01 -
Wash the rhubarb thoroughly and chop into small pieces to mix evenly into the batter.
02 -
In a small saucepan, melt the butter over low heat. Stir in chocolate chips until smooth and creamy.
03 -
In a mixing bowl, sift together cocoa powder, flour, sugar, and salt.
04 -
Add eggs, vanilla extract, and the melted butter-chocolate mixture to the dry ingredients. Fold until just combined.
05 -
Mix the rhubarb chunks into the batter, pour into a greased baking pan, and bake at 350°F (175°C) for 35 minutes.