Step 1

In the bowl of a stand mixer or hand mixer cream butter and shortening for about 2 minutes, until light and fluffy.

Step 2

Add cornstarch to the hot water and add it to the creaming mixture.

Step 3

Continue to cream until it's a smooth mixture again.

Step 4

Add vanilla extract and combine well.

Step 5

Finally, start adding the powdered sugar one cup at a time.

Step 6

Once all the sugar is in - whip the buttercream for a good three minutes until light and fluffy.