In a bowl, beat the ricotta, sugar, and flour till mixed. Add peels and salt, beat until smooth. In another bowl, beat eggs until thick and lemon colored, about 5 minutes, slowly fold into ricotta mixture. Gently mix in remaining ingredients. Pour into the crust. Bake at 350 degrees for 55 minutes or until a knife inserted near the center comes out clean. Cool. Store in the refrigerator.