In a large bowl or the bowl of a standing mixer, mix together flour, brown sugar, baking powder, and salt.
Add in the butter. Using a pastry cutter, fork, or your stand mixer, work the butter into the flour mixture until the mixture resembles coarse crumbs.
Next, add in the egg, heavy cream, sour cream, and vanilla extract. Mix until combined.
Lastly, add in the peaches. Gently mix the dough together until the peaches are combined.
Turn the dough out onto a floured surface, and pat the dough into a flat circle (about a 1/2” to 3/4” thick).
Press the crumb cake topping onto the top of the peach scone dough.
Next, cut the dough into 8 triangles. Using a spatula, place the peach scones on the parchment paper, making sure they are evenly spaced apart.
Bake for 18-20 minutes, or until the scones are lightly brown on top.