- Preheat the oven to 375° F
- Spray a 15 X 10 inch jelly roll pan with non-stick spray. Line the pan with parchment paper then spray the parchment paper with non-stick spray.
- Place a mesh strainer over a bowl and place the flour, baking powder, baking soda, pumpkin pie spice and salt into the strainer and sift into the bowl. Sifting the dry ingredients will ensure that any lumps will be removed from the einkorn flour which tends to clump easily.
- Combine the eggs, egg white and coconut sugar in a large mixing bowl and beat until thick, about 3 minutes. Beat in vanilla extract and pumpkin puree. Fold in flour mixture until well combined. Spread evenly into the prepared jelly roll pan.
- Bake for 11 to 14 minutes until the cake springs back when touched.
- Immediately run a knife along the edge of the pan to loosen the cake from the pan.
- Dust the top of the cake with confectioner's sugar and place a kitchen towel over the sugar. Place a baking sheet or plastic cutting board over the towel and flip the cake over so the bottom of the cake is on top.
- Gently peel off the parchment paper and roll the cake in the towel jelly-roll style, starting with a short side. Cool completely on a wire rack.
- In a stand mixer, fitted with a whisk attachment, add the mascarpone cream, powdered sugar, salt and rum. Whisk together just briefly until smooth. Stop the motor and scrape down the sides and bottom of the bowl. With the mixing speed on low, add the heavy cream and slowly raise the speed and beat until the mixture is thick and creamy and has formed firm peaks.
- Unroll cake. Spread the mascarpone cream evenly over cake to within 1 inch of edges. Roll up again and place seam side down on a serving platter. Cover and refrigerate for 1-2 hours. Sprinkle with powdered sugar before serving. Store in the refrigerator. Yield: 10-12 servings.
NOTES:* Make sure you measure your jelly roll pan. This recipe calls for a 10 x 15 inch jelly roll pan. If you use a larger pan the cake will be too thin. The side of the jelly roll pan should be ¾ inch high.* Whole eggs will whip up with much more volume if they are brought to room temperature before you whip them. You can bring them to room temperature quickly by placing them in a bowl of warm water for a few minutes before you crack them open.
* You can substitute brown sugar for the coconut sugar.* Rolling the cake up while it is still warm is an important step to ensuring success with the cake roll. It will roll very easy while it is still warm then once it cools and is unrolled and covered with the filling, it will 'remember' its shape and re-roll without any trouble.