Preheat oven to 375. Beat eggs, squash, orange pulp, orange zest, vanilla, sugar and stevia mixture until fluffy. Add the flour and baking powder and continue to blend well. Set aside.Prepare a 9 x13 baking sheet or jelly roll pan with lightly greased butter. Place parchment paper over the baking sheet and lightly grease the top with butter. Add the batter and spread it evenly, bake for 10 minutes. Meanwhile, lightly sprinkle a dish towel with powdered sugar. When the cake is done, carefully turn onto the dish towel. Cover and gently roll into a tight roll. Place it in the freezer for 15 minutes. As the cake is cooling, combine softened cream cheese, remaining orange pulp and zest, vanilla and powdered sugar in a bowl. Whip until smooth and creamy. When the cake is cooled, unroll it and apply the cream cheese filling. Roll it up as tight as you can and sprinkle with powdered sugar. Wrap in plastic wrap and refrigerate until ready to serve.