In a bowl, sift the flour, salt, baking powder, and 2 tbsp of sugar
Then add in the cold cubed butter and mix it in using a pastry cutter or fork.
Add in the cold cubed cream cheese and form the dough into a flat disk shape. If the dough is too crumbly to form, add 1 tbsp of ice-cold water. Careful not to overwork the dough.
Wrap the dough with plastic wrap and chill in the refrigerator for about 30 minutes.
Slice the peaches about 1/4" thick and add them into a bowl. Add the cornstarch and 4 tbsp of sugar and gently mix just to combine.
On a floured surface, roll the dough out to a circle about 12-13" in diameter. Using a rolling pin, transfer the dough onto a baking sheet lined with parchment paper. If some of the dough crumbles, just patch up cracks using your clean hands.
Begin arranging the sliced peaches into a fanned-out style starting from the outside in. To make it faster you can just dump out all the peaches and leave it that way. Be sure to leave about 2 inches of space as the border.
Fold the edges of the dough over onto the peaches. With each fold slightly pinch the dough to keep it all together.
Brush the dough with egg wash (1 egg + 1 tsp water, whisked) and sprinkle with some raw coarse sugar on top of the dough. (Sprinkling raw sugar is optional).
Preheat your oven to 400 degrees Fahrenheit and bake for 20-25 minutes. Baking time may vary depending on the oven. Serve warm with vanilla ice cream.
Notes
Use cold butter- Cold butter holds air better than softened butter, which gives the crust a flaky texture. It also keeps it from getting greasy, as melted butter would.
Patch any cracks in the dough- If cracks appear once you've transferred the dough to the baking pan, use clean hands to repair and smooth them out.