Preheat oven to 450°. Line a baking sheet with parchment paper.
Using a serrated knife, cut baguette on the diagonal into ½-inch slices. Place slices on prepared pan. Brush each side of bread evenly with olive oil. Bake until lightly crisp and golden, 3 to 5 minutes. Let bread cool for at least 10 minutes.
Using a sharp knife, cut tangerine into sections. Peel away the skin and cut each slice in half.
Spread 1 teaspoon ricotta on a crostino. Sprinkle ⅛ teaspoon salt and ⅛ teaspoon black pepper. Top with smoked salmon and a piece of tangerine. Repeat with remaining crostino and toppings. Garnish with microgreens, if desired. Serve immediately.
Recipe by Victoria at https://victoriamag.com/tangerine-crostini/