1. Combine flour, baking powder and fine salt in a bowl. Stir in yogurt until dough comes together, then turn out onto a clean, lightly floured surface and knead just until dough feels elastic, about 3 minutes. Return dough to bowl, cover with plastic and let rest for 30 minutes. 
  2. Preheat the oven to 400°F. Divide dough into 4 equal pieces and roll each piece out into an oval about 8-inches long and place on a parchment-lined baking tray. Stir ricotta, honey, thyme, garlic and a little pepper together and spread over each flatbread. Toss zucchini with olive oil and season lightly. Fan out zucchini slices so they overlap and cover the ricotta. Bake the flatbreads for about 15 minutes, until lightly browned on the bottom and zucchini is tender. Serve warm, cut into slices.