Grease a standard size jelly roll pan, then line with waxed paper and grease the paper. That will assure that none of your cake will stick to the waxed paper.
In the bowl of a hand or stand mixer, beat eggs and vanilla on high speed for 5 minutes, or until lemon-colored. Turn speed to medium and gradually add sugar, beating until dissolved.
In a medium bowl, combine flour, baking powder and salt. Fold gently into egg mixture just until combined. Pour batter into prepared jelly roll pan and use a spatula to spread it evenly across the pan.
Bake for 10-12 minutes or until light brown and edges start to pull away from sides of pan. Turn hot cake out, waxed paper side up, onto a lint free, clean kitchen towel that has been well dusted with confectioners’ sugar. Peel waxed paper away from cake, Starting on short side of cake, roll up cake tightly into the towel and allow to cool completely.
MAKE FILLING:
Place metal mixing bowl and whisk attachment (or beaters for a hand mixer) into the freezer for 10 minutes.
Place heavy cream into chilled bowl and whip on high speed until soft peaks have been formed. With mixer still running on high speed, lightly sprinkle sugar into cream and continue mixing on high for 2 minutes, or until light and fluffy.
ASSEMBLY:
Unroll cake from towel and use a spatula to spread whipped cream evenly over the cake. Use an offset spatula or knife to apply jam in an even layer on top of whipped cream. Roll up the cake again and refrigerate for 2 hours before serving. Sprinkle with confectioners’ sugar and garnish with blueberries and additional whipped cream, if desired.