Heat oven to 350°F. Mist a 10-inch tube pan with the vegetable oil spray and set aside.
In a large mixing bowl, combine cake mix, pudding, yogurt, canola oil, and buttermilk. Add remaining ingredients and blend with an electric mixer, scraping the sides of the bowl as needed. The batter should be thick and well blended. Pour the batter into the prepared pan and smooth with a rubber scraper.
Bake for 45 to 50 minutes until golden brown and cake springs back when pressed lightly with your finger. Cool for at least 30 minutes before removing cake from the pan.
Use a sifter or tea strainer to dust cake with powdered sugar. Garnish with raspberries and candy leaves from the New York Baking Company (212-675-2253).