To make the cupcakes: first whisk together the flour, sugar, cocoa, baking powder and salt in a bowl till well mixed. Keep aside.
Put the puréed beets, oil, lemon juice and vanilla extract into another bowl and lightly whisk together till mixed well.
Pour this into the bowl with the dry ingredients and mix just enough to combine. Divide the batter equally between 6 cupcake tins lined with paper cups.
Bake the cupcakes at 180C for about 20 to 25 minutes. A skewer/ toothpick inserted into the center should come out clean once they?re done. Cool completely and frost with cream cheese frosting.
To make frosting: Combine cream cheese and butter in a bowl for an electric mixer. Beat on high until light and fluffy, a couple of minutes. Add the sifted confectioners? sugar and vanilla and beat on low at first, then increase to high. When frosting is light and airy ? it is ready to put on top of the cupcakes.