In a food processor fitted with the large blade, combine flour, semolina, salt, baking powder and sugar. Add butter. Pulse several times until mixture resembles course meal. In a small bowl, whisk together egg yolks, cream, orange zest and water. Pour into flour mixture and pulse several times. Mixture will still be loose.
Turn onto table or board and knead several times until mixture comes together. If it seems too dry, sprinkle with another tablespoon of cold water. Flatten into a disc and cover with plastic wrap. Chill for 30 minutes.
For filling, in a bowl fitted with paddle attachment combine the ricotta, mascarpone, sugar and maple syrup. Beat on medium speed, about two minutes, until creamy and smooth. Scrape down sides and beat for another thirty seconds until blended. Add remaining ingredients and beat on low speed for another minute just until smooth and blended, scraping down sides once.
Preheat oven to 375 F. Roll out dough into a 15X11 oval shape. Dough should be about six milliliters thick Place into a 13x9x2 oval dish so that pastry hangs over the edge by about five centimeters. Pour in filling and fold over edges of pastry. Bake for about 45 minutes, until golden and filling is just set. Cool. Dust with icing sugar and serve at room temperature. Serve with dollop of whipped cream if desired.