In a medium bowl combine ricotta, pecorino, breadcrumbs, pepper, and salt. Fill a piping bag with mixture. Snip off about 1/2 inch from the tip.
Clean, and and dry your squash blossoms. Remove the stamen. Fill squash blossoms with ricotta mixture about halfway up the blossom. Use the leaves to enclose the blossoms. Set aside on a sheet tray or plate.
Heat oil in a large pot over medium heat until temperature reaches 350°F.
In a large bowl whisk flour and baking powder. Add seltzer and whisk until few lumps remain. The mixture she have a loose pancake consistency. Dip stuffed squash blossoms into batter. Immediently and carefully place the battered blossoms into the pot. Fry in 2 to 3 batches, 3 to 4 minutes each or until aerated, crispy and lightly golden. Flip halfway through if not fully submerged.
Remove squash blossoms to a paper towel lined plate. Sprinkle with maldon or kosher salt.