Cut the butter and cream cheese into 1 inch cubes.
Using a stand mixer mix add the butter and cream cheese into the flours and mix until a ball forms.
Divide into 3 separate balls and refrigerate for 8 hours or overnight.
for the cherry filling
Combine the cherries and sugar in a small saucepan. Bring to a simmer over medium heat, stirring occasionally but keeping your eye on it.
Sprinkle the corn starch over the mixture and use a whisk to break up any clumps. Let simmer and thicken for about 15 minutes.
Stir in salt and almond extract.
Remove from heat and let cool before spreading onto pastry. This can be made in advance and refrigerated for a few days.
assembling strudel
Grease a sheet pan and preheat oven to 350.
Remove one of the balls of dough from the fridge and let stand at room temp for 5 minutes. As it rests, flour a surface and get out a rolling pin.
Roll out the dough into a 10 x 8 rectangle.
Add 1/3 of the cherry filling and spread over the top. Sprinkle the top of the filling with about a tablespoon of almond flour.
Starting at the long edge roll the pasty into a large roll (not as tight as a cinnamon roll). Use a touch of water to pinch the seam and ends together to seal.
Place the strudel on a greased baking sheet and refrigerate.
Repeat with remaining 2 pastry balls and jam. Freeze or bake off (only put 2 on a baking sheet at a time).
Place 1 or 2 of the strudels on a baking sheet together.
Whisk the egg and use a pastry brush to brush some egg onto the pastry.
Sprinkle the pastry with almonds then use a sharp knife to make a few diagonal slits in the top of the pastry.
Bake for 30-35 minutes or until golden brown.
Let cool then sprinkle with powdered sugar.
To serve, cut crosswise into six pieces.
Notes
Strudels may be made then frozen before baking or you may freeze the dough and make the jam in advance.