Preheat oven to 375°F (190°C).

In a medium bowl, whisk together granulated sugar, buttermilk, ricotta, oil, eggs, lemon zest and juice, and vanilla.

In a large bowl, whisk together flour, poppy seeds, baking powder, salt, and baking soda. Fold in sugar mixture just until combined and no flour pockets remain. (Batter will still be lumpy; do not overmix.)

Spray 10 to 12 wells of a standard muffin pan with cooking spray; fill each until batter is about ¼ inch from top edge of well (about ⅓ cup [about 87 grams] each). Sprinkle with sparkling sugar.

Bake until a wooden pick inserted in center comes out clean, 14 to 18 minutes. Let cool in pans for 5 minutes. Remove from pan, and serve warm, or let cool completely on a wire rack.