Peel peaches (I mince up the peels for our chickens), then halve and pit each. Cut each half into 4 slices. Gently toss peaches and sugar together in a large bowl; let stand for 30 minutes, tossing several times. Drain peaches in colander set over large bowl. Whisk 1/4 cup of the drained juice (I rarely have more 1/4 cup juice, but if you do, save it for a morning smoothie), cornstarch, lemon juice, and salt together in a small bowl. Toss peach juice mixture with peach slices and transfer to 8-inch square glass baking dish. Bake until peaches begin to bubble around edges, about 10 minutes.
For the topping:
While peaches are baking, in food processor, pulse flour, 3 TB sugar, baking powder, baking soda and salt to combine. Scatter butter over and pulse until mixture resembles coarse meal – about ten 1-second pulses. Transfer to medium bowl; add yogurt and toss with rubber spatula until cohesive dough is formed. Do not over mix dough or biscuits will be tough. Also – don’t prepare the biscuit dough any sooner than recipe indicates, as the biscuits will not rise properly.
To assemble and bake:
Adjust the oven rack to the lower-middle position and heat to 425 degrees.
After peaches have baked 10 minutes, remove them from the oven. Divide dough into 6 evenly sized but roughly shaped mounds and place on top, spacing them at least 1/2 inch apart (they should not touch – stagger the rows slightly). Sprinkle each mound with a portion of remaining 1 tsp. sugar. Bake until topping is golden brown and fruit is bubbling, 16 – 18 minutes (I usually do at least 18 minutes in my oven. Less time leaves the bottom of the biscuits a bit gooey). I love serving the cobbler hot, cooling it a few minutes on a wire rack so no one gets burned, with ice cream on top. Leftovers can be reheated in a 350 degree oven until warmed through (but it is best right out of the oven when the biscuits are a bit crunchy outside, delicate and tender inside and the peaches are like a slice of the summer sun.