Step 1

Place a medium saucepan over medium heat. Add the flour, sugar, and salt. Whisk for about 1 minute to combine.

Step 2

Add milk and whisk. Once the mixture is hot, lower the heat to medium-low. Whisk until the roux has thickened and reaches a pudding or custard-like consistency. It will take about 10 to 15 minutes. Make sure to whisk constantly to prevent the mixture from burning. (DON'T crank up the heat!)

Step 3

Remove the roux from the heat and transfer it to a shallow bowl. Cover it with plastic wrap. Push the wrap to touch the surface of the mixture to prevent the skin from forming on the surface. Allow the mixture to cool down COMPLETELY. It will take about 1 hour, but here’s a simple trick: add a few ice cubes on top of the plastic, and your roux should be cool enough within 10 minutes.

Step 4

Soften up the butter quickly. Cut your butter into ¼-inch slices and place them on a flat plate in one single layer. Microwave them at 50% power at 5-second intervals. Check after every 5 seconds until they are nice and soft. It usually takes less than 30 seconds in total. To check whether the butter is ready: if a spatula can cut through the butter easily, your butter is ready.

Step 5

Beat the softened butter in a large mixing bowl until smooth and creamy. You can use a hand mixer or a stand mixer.

Step 6

Add the cooled roux GRADUALLY the the butter, about 1-2 tablespoons at a time. Beat until light and fluffy.

Step 7

Mix in the vanilla extract, and give it a quick mix. Use a spatula to scrape down the sides from time to time.

Step 8

Frost immediately or store in an airtight container in the fridge.