Grease and lightly flour a 8 x 8 x 5 cm baking pan; set aside. For filling, in a small mixer bowl, combine cream cheese and one third cup of the sugar. Beat with electric mixer on medium speed until fluffy. Add 1 egg and beat mixture until smooth; set aside. In a large mixer bowl, stir together biscuit mix, one third cup sugar and spice. Add carrot, zucchini, oil, 2 eggs and vanilla. Beat on low speed for 30 seconds. Beat on medium speed for 2 minutes. Pour half the batter into prepared pan. Spoon filling atop. Spoon remaining batter over filling. Bake in a 350 degree oven for 35 to 40 minutes or until done. Cool on wire rack. To serve, sift powdered sugar over cake, if desired. Cut into squares.