Preheat oven to 400°. Line a rimmed baking sheet with parchment paper.
Snap off and discard tough ends from asparagus spears. Arrange asparagus on prepared baking sheet.
Bake until asparagus is tender when pierced with the tip of a sharp knife, 5 to 7 minutes. Let cool completely. Cut spears in half vertically and then into ½-inch pieces.
Reduce oven temperature to 350°. Line another rimmed baking sheet with parchment paper.
Place baguette slices on prepared baking sheet.
Toast until baguette slices are very lightly golden brown and crisp, 5 to 7 minutes. Let cool completely.
Spread Lemon-Dill Aïoli onto toasted baguette slices. Ruffle ham slices to fit baguette slices. Arrange asparagus pieces cut side down on top of ham.
Garnish with dill sprigs, if desired.
Recipe by TeaTime Magazine at https://teatimemagazine.com/asparagus-and-ham-tartines/