01 - Preheat the oven to 425°F.
02 - Arrange the asparagus spears in a single layer on a baking sheet. Drizzle with olive oil, then sprinkle with salt and pepper. Toss to coat evenly.
03 - Roast in the preheated oven for 12–15 minutes, or until the asparagus is tender and slightly caramelized, shaking the pan halfway through.
04 - In a heatproof bowl, whisk together egg yolks and lemon juice until the mixture is thickened and doubled in volume.
05 - Set the bowl over a saucepan of barely simmering water (do not let the bowl touch the water). Continue whisking constantly.
06 - Slowly drizzle in the melted butter, whisking continuously until the sauce is thick and creamy.
07 - Remove from heat and whisk in salt and cayenne pepper.
08 - Serve the roasted asparagus immediately, drizzled with hollandaise sauce.