2Tbspbuttermilk, (or 2 Tbsp milk with ½ tsp lemon juice/white vinegar)
1tspwhite vinegar
1tspvanilla extract
2Tbspred food coloring
½cup(60g)powdered sugar, for dusting
Cream Cheese Filling:
8oz(226g)cream cheese, cold
6Tbsp(85g)butter, lightly softened
1tspvanilla extract
2 ½cups(300g)powdered sugar
Instructions
Preheat oven to 350˚F. Grease 15x10" jelly-roll pan; line with wax paper. Grease & flour paper. Sprinkle a thin, kitchen towel with approximately ½ cup powdered sugar (a heavy coating.)
In a bowl, sift together flour, cocoa, baking powder, & salt. Set aside.
In the bowl of a stand mixer using the whisk attachment, whip eggs on medium speed for 5 minutes. Slowly add sugar & oil. Beat until combined. Add buttermilk, vinegar, vanilla, & red food coloring. Stir in flour mixture until combined. Spread evenly into prepared pan.
Bake in preheated oven for 13-15 minutes or until top of cake springs back when touched.
Immediately loosen & turn cake onto prepared towel. Carefully peel off wax paper. Roll up cake & towel together from each end meeting in the center. Turn cake onto it's side so both rolls are stacked one on top of the other. Gather ends & tie shut using a rubber band. Allow cake to rest on it's side on a wire rack until cool.
To make the filling: Using the paddle attachment of your stand mixer, beat cream cheese & butter until incorporated & smooth. Should not take more than 1 minute. Add vanilla & powdered sugar all at once. Mix until combined.
Carefully unroll cake. Spread cream cheese mixture over the cake leaving a generous amount down the seam where the two rolls meet (this will be the bottom point of the heart, so you want extra icing there.) Re-roll each end as tight as you can until both ends meet in the center. Stack rolls on it's side, one on top of the other, & slice. If needed, gently help shape the cake into a heart & serve.