Filled Cupcakes with Cocoa Frosting

1 . Stage

Preheat the oven to 350 degrees F (175 degrees C). Line a 12-cup muffin tin with paper liners.

2 . Stage

Sift flour, cocoa powder, baking soda, and salt for cupcakes together into a medium bowl. Combine mayonnaise, sugar, milk, and vanilla extract in a large bowl; beat with an electric mixer until smooth. Slowly add flour mixture and beat at medium speed for 2 minutes. Divide batter evenly amongst the prepared muffin cups.

3 . Stage

Bake in the preheated oven until tops spring back when lightly pressed, 25 to 28 minutes. Cool in the tins for 5 minutes. Transfer to a wire rack and let cool completely, about 30 minutes.

4 . Stage

While the cupcakes are baking, stir together flour and salt for the filling in a small saucepan. Gradually whisk in milk. Cook and stir over medium heat until thick and pudding-like, 5 to 10 minutes. Remove from the heat, cover, and refrigerate until cold, about 30 minutes.

5 . Stage

Cream shortening and confectioners' sugar together until light and fluffy. Gradually mix in chilled pudding mixture and vanilla extract, beating until light and fluffy. Transfer filling to a pastry bag fitted with a small tip.

6 . Stage

Push the pastry tip into the top of a cupcake about 1 inch deep. Squeeze filling to fill cupcake, stopping before it starts to leak outside of the hole. Repeat to fill remaining cupcakes.

7 . Stage

Combine butter, milk, and cocoa powder for the frosting in a saucepan and bring to a boil over medium heat. Remove from the heat and transfer to a mixing bowl. Immediately add confectioners' sugar and vanilla extract; beat well. Frost cupcakes with warm frosting.