Preheat your oven to 425°F. Lightly butter or grease a 9" x 13" pan., In a medium bowl, combine the fruit, melted butter, and lemon juice, tossing to coat the fruit. , In a separate small bowl, whisk together the sugar and thickener, then sprinkle over the fruit., Toss gently with a spatula until the fruit is coated, then scoop the fruit into the pan. Pat the inside of the bowl with a clean towel so it's mostly dry., In the same mixing bowl, whisk together the flour(s), sugar, baking powder, and salt. In a separate bowl or a liquid measuring cup, whisk together the melted butter, milk, egg, and almond extract. Pour the wet ingredients into the dry and mix just until thoroughly combined., Dollop the biscuit topping in blobs atop the fruit (3 across and 4 down in a 9" x 13" pan), leaving 1/2" or so between them. Fill in the in-between spaces with any leftover dough. Sprinkle with sugar., Bake the cobbler for 20 minutes. Reduce the oven temperature to 375°F, and bake for an additional 25 minutes, until the biscuits are golden and the filling is bubbly. (Be sure to bake until the biscuits are a deep golden brown, otherwise the biscuits in the center may be under-baked.) Remove the cobbler from the oven and let it cool slightly before serving warm or at room temperature., Store leftover peach cobbler, covered, in the refrigerator for up to 5 days.