Preheat oven to 400F. Cut off the bottoms of the asparagus stalks. These are usually much thicker and harder than the rest of the stalk, and they aren't as nice to eat once they come out of the oven. I generally cut off the part that's lighter in color. The bottom of the stalk is also harder to cut through.

Separate the asparagus into bundles of approximately equal thickness.

Wrap each bundle in a strip of bacon: Holding the tops of the spears, wrap the bundles in bacon starting at the bottom, twisting until the entire slice is wrapped around.

Transfer the bacon-wrapped asparagus onto a baking sheet lined with foil. Drizzle over the olive oil and season with salt, pepper, and red pepper flakes.

Bake for 20–22 minutes and then broil for an additional 2–5 minutes, until the bacon is crispy and cooked.

Remove asparagus from the oven and let cool slightly.

In a small container, combine the rendered fats from the baking sheet with minced garlic, egg yolk, and lemon juice.

Add the mayonnaise and salt and mix together until the aioli is smooth.

Serve the asparagus with aioli on the side (or lathered on top!).