In the bowl of a stand mixer, beat the butter on medium speed until light and creamy, about 2 minutes. Scrape the sides of the bowl, add the sugar, and beat for an additional 2 minutes until the mixture is fluffy. Scrape the sides of the bowl and add one whole egg and the egg yolk, beating on medium speed just until combined. Scrape the bowl and add the dry ingredients. Beat on low speed just until combined. Be careful to not overbeat.
Dump the dough out onto a lightly floured surface and divide the dough in half. Place one of the halves in between two large sheets of parchment paper and use a rolling pin to roll the dough out into an 11” circle. Set aside and place the second dough ball in between two separate sheets of parchment paper. Roll the second dough piece into a 9” circle. Place both on a flat surface in the fridge and allow to cool for an hour.
Preheat the oven to 375 degrees and move a rack to the upper third of the oven. Grease the insides of a 9×2” cake pan and trim a parchment paper round to line the bottom of the pan.
Remove the dough from the fridge and allow them to sit out for a few minutes to become pliable. Peel the parchment paper off of the 11” round dough and center it into the greased pan. Gently press the dough into the bottom of the pan and around the edges. Trim off any excess, allowing the dough to travel only halfway up the sides of the pan. Spread the cherry jam in the pan, leaving a ½” border around the edges of the pan. Peel the top parchment paper off of the 9” circle and use a paring knife to trace and trim a circle the diameter of the cake pan in the dough. Transfer the trimmed dough into the cake pan and pinch the edges of the two dough pieces together to seal in the jam. You can wet your fingers lightly to pat out the dough to make it as even as possible. Don’t sweat it if your dough isn’t perfect though.
Whisk together the remaining egg with 2 teasopons of water and use a pastry brush to paint a thin layer of the egg wash over the top of the pie. Place in the oven and bake for about 30 minutes or until the top is golden brown and set. Allow the pie to cool in the pan for 10 minutes and then carefully move a paring knife around the border of the pie to release the edges. Invert the pie onto a cooling rack and then carefully flip back over onto your serving plate. Allow to cool completely.
Once ready to serve, garnish with sliced fruit or powdered sugar. Serve immediately.