Preheat the oven to 375 degrees F.
For the asparagus: Toss the asparagus with the olive oil on a rimmed baking sheet and season with salt and pepper. Roast until slightly tender to the bite, about 10 minutes.
For the hollandaise: Meanwhile, add the egg yolks, lemon juice, salt and cayenne to a small food processor or blender and blend on low. Slowly add the melted butter in a steady stream, blending until thickened. Serve over the roasted asparagus.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.