Step 1

Add egg yolks, lemon juice, Dijon, salt and cayenne pepper to blender. Set aside.

Step 2

Add butter to a glass measuring cup and cover with a paper towel or plastic wrap (so it doesn’t splatter). Heat butter in the microwave for about 1 minute, or until completely melted and very hot.

Step 3

Cover blender and blend mixture (without butter) at top speed for 20 seconds. Reduce to low and remove the vent from the blender lid and continue to blend while pouring in melted butter in a slow steady stream then immediately cover.

Step 4

Increase speed to highest power and blend until thickened. If it isn’t thick, just keep blending on high until thickened.

Step 5

Keep the sauce warm until serving by placing the blender container in a pot of hot water.