Peaches n' Cream Jelly Roll

I'm not sure what made me start making jelly rolls as a teenager nor why I stopped making them.  Recently someone asked me to identify what a jelly roll pan looked like because they needed to bake something for a function.  I asked if they had ever had a jelly roll and was amazed that they had not.   I didn't dare ask if they had ever experienced a baked Alaska.  It's all good since now I get to cross another item off my recipe bucket list for the year and this is an upgraded version using icing from the plain ones I used to bake.  

Peaches n' Cream Jelly Roll

4 eggs at room temperature, separated
1 cup sugar
1/2 cup flour, sifted
1 tsp baking powder
1/2 tsp vanilla
1/2 cup peach preserves (do yourself a favor and use a good kind)

Icing

3 tbsp butter, softened
4 ounces mascarpone 
1/2 tsp vanilla
1 cup powdered sugar

Start off by greasing your jelly roll pan.  Place a layer of wax or parchment paper down (cut to size) at the bottom of the pan and grease that also.  

In a small bowl, beat the egg yolks with 1/2 tsp vanilla until thick (at least 3 minutes) and then beat in 1/2 cup of sugar.  In a larger bowl, whip the egg whites until they form a soft peak.  Gradually beat in the other 1/2 cup of sugar.  Put away the mixer until it's time to make the icing.

Gently fold in the egg yolk mixture into the egg whites.  Gradually add in sifted flour and baking powder.  You don't want to over 5but make sure the flour isn't hiding into any little air pockets.  Spread out over jelly roll pan.  Bake for 10-12 minutes (it's done when you can touch the middle and it doesn't indent) at 375°.  Gently cut along edges to make sure it doesn't stick to the pan.

Cover the pan with a clean kitchen towel.  Hold towel tight across and turn over.  Carefully remove the wax/parchment paper.  Roll up the cake in the towel and allow to cool completely on a rack.

Time to make the icing.  In a medium bowl, mix together butter and mascarpone.  Gradually add in powdered sugar (covering the bowl slightly with your spare hand will save you clean up later because the powdered sugar likes to fly.  Mix in 1/2 tsp of vanilla last.

When cool, carefully unroll the cake.  Cut off any dried edges.  Spread the cake with the peach preserves and then a layer (approximately 1/2) of the icing.  Reroll the cake and place the icing on the outside.  Cut into slices approximately 1/2 to 3/4" thick.