1. Preheat the oven to 475°F (250°C). Place a rack in the lower part of the oven. Line the baking sheet with parchment paper.
2. In a large bowl, place yogurt, olive oil and salt and mix. Add flour and baking powder and mix well.
3. Flour a work surface and a rolling pin. Transfer the dough to the work surface and form a ball. Roll the dough into a rectangular flatbread 0.5 cm (quarter inch) thick. Transfer to a baking sheet. Bake for 12 to 15 minutes until the flatbread is golden brown. Set aside on a baking sheet.
4. Reduce oven temperature to 400°F (200°C). On another baking sheet, place squash rings and toss with 1 tbsp (15 mL) extra virgin olive oil, rosemary and salt and pepper to taste. Bake for 20 to 22 minutes, turning halfway through cooking, until tender and golden. Set aside.
5. In a medium skillet, heat 1 tbsp (15 mL) extra virgin olive oil over medium heat. Add chopped onions, a pinch of salt and toss to coat all onions with oil. Let the onions cook until soft and golden, about 20 minutes. Add 1 to 2 tbsp (30 mL) of water to the pan as the onions dry, to prevent burning. Once golden brown, add balsamic vinegar and reduce for about 5 minutes more. Set aside.
6. To assemble the flatbread: Spread a thin layer of mascarpone on the flatbread. Top with squash and caramelized onions. Return flatbread to the preheated oven and bake for 5-7 minutes until heated through. Garnish with arugula, a pinch of sea salt, rosemary and a drizzle of extra virgin olive oil before slicing and serving.

Recipe in collaboration with Vanessa Perrone, vanessaperrone.com