Preheat oven to 350 F. Butter 10x15 baking sheet, fit with parchment paper, then butter parchment paper. Set aside.
Make the batter: In a stand mixer fitted with a whisk, whip egg whites until fluffy. Slowly add sugar, whipping on high until stiff peaks form. Change to paddle attachment. Add yolks one at a time while mixing on speed 2, then add pumpkin and mix another 10 seconds.
Sift flour baking powder and baking soda together. Slowly add in dry ingredients to wet batter. Increase to speed 3 and add vanilla and cinnamon. Pour batter onto prepared baking sheet. Transfer to oven and bake for 12 minutes or until a toothpick inserted in the center of the cake emerges clean. Remove cake from pan and place top side down over a clean moist kitchen towel. Carefully remove parchment paper, then roll cake in towel. Let rest for 10 minutes.
Make the filling: Meanwhile, using a clean bowl and whisk, combine heavy cream, sugar and panela. Whisk until a thick heavy cream forms. Drizzle in rum and whisk a few times until integrated. Refrigerate until ready to use.
Once cake has completely cooled, roll out and fill with 2/3 of Rum Panela Cream. Re-roll tightly and plate.
Mix pecans and panela in a small bowl. Pour remaining whipped cream over cake and sprinkle with pecan panela mixture. Slice and serve.