Set your oven to 400°F and line a baking sheet with parchment paper. Getting the oven properly hot before the tart goes in is what gives you that shatter-crisp bottom crust. I always let mine preheat a full ten minutes before baking anything with puff pastry.

Lay your thawed puff pastry sheet onto the prepared baking sheet and gently unroll or flatten it with a rolling pin if needed. Using a sharp knife, score a border about half an inch in from the edge, cutting only partway through the dough. This scored line is what lets the crust puff up beautifully around the filling.

In a bowl, whisk together the goat cheese, cream cheese, egg, garlic powder, thyme, salt, and pepper until smooth and creamy. I like to soften the cheese at room temperature first so it blends without any lumps. This filling is really the flavor backbone of the whole tart.

Spoon the cheese mixture inside the scored border and spread it evenly with a spatula. Keep it a little thinner near the edges so it bakes evenly. Leaving that clean border bare is what gives you a defined, golden crust once it's out of the oven.

Toss the trimmed asparagus spears with olive oil, salt, and pepper, then lay them over the cheese filling in a single layer. I alternate the direction of the tips for a prettier finish, though straight rows work just as well. If your spears are thick, slice them in half lengthwise so they cook through in time.

Sprinkle the grated Parmesan generously over the asparagus, then brush the exposed pastry border with the egg wash. This little step is what gives the crust that shiny, bakery-style golden color once it bakes.

Slide the tray into the oven and bake for 20 to 25 minutes, until the pastry is puffed, golden, and the asparagus is tender with lightly charred tips. I always rotate the pan halfway through so it browns evenly all around.

Let the tart rest on the pan for about 5 minutes before slicing. This short rest helps the filling set so your slices hold together instead of sliding apart on the plate.