I put watercress in doughnuts. Indeed. And I'll do it again. These zesty grapefruit baked doughnuts are vibrant, green-flecked spongy bursts of summer. When cooked, the watercress loses the pepperiness and turns more floral, lending these doughnuts a subtle earthiness to compliment the gutsy kick of the fruit. What are grapefruit pearls, you ask? I