Vertical Cake (Lemon & Blueberry

1213 minutes or until cake is set and the top springs back when lightly poked with your finger. Do not overbake.
As the cake bakes place a piece of parchment paper a little larger than the cake or a thin kitchen towel flat on the counter. Using a sifter dust with a light coating of confectioners sugar.
Roll the cake Once the cake comes out of the oven run a thin knife along the edges to help release the cake then immediately invert it onto the parchmenttowel. Peel off the parchment paper that was on the bottom of the cake as it baked. Using a sifter dust surface with a light coating of confectioners sugar. Starting with the narrow end slowly and gently roll the cake up with the parchmenttowel. The cake will be warm. Allow the cake to cool completely rolled up in the parchmenttowel. Place in the refrigerator to speed it up about 23 hours.
As the cake cools make the blueberry sauce The blueberry sauce must be completely cool before folding into the whipped cream so make it ahead of time or when the cake is cooling. Mix the cornstarch and water together in a very small bowl. Set aside. Combine blueberries lemon juice and granulated sugar together in a small saucepan over mediumlow heat. Stir constantly bursting the blueberries against the sides of the pan. Once the blueberries have released some liquid add the cornstarchwater. Turn the heat up to medium. Stir and cook for 3 minutes. Remove from heat and allow to cool completely. Mixture will thicken as it cools. I place it in the refrigerator to cool down quicker.
Remove the cake roll from the refrigerator and allow to sit on the counter for a few minutes to warm up as you prepare the whipped cream.
Make the whipped cream Using a hand mixer or a stand mixer fitted with a whisk attachment whip the heavy cream and confectioners sugar together on mediumhigh speed until medium peaks form about 34 minutes. Medium peaks are between softloose peaks and stiff peaks. Using a spoon or rubber spatula gently fold in cooled blueberry sauce. If you want blueberry swirls as pictured dont completely combine the two. Only fold together a few times. Place in the refrigerator until ready to use.
Assemble vertical cake Slowly and gently unroll the cake. If you notice the cake cracking unroll slower and gently press the cracked pieces back