In a small bowl, mix together the yeast, 1 teaspoon sugar and water to bloom. Set aside.
In a large measuring cup, whisk together the buttermilk, butter and eggs. Set aside.
Mix the flour, remaining sugar, yeast mixture and salt in the bowl of an electric mixter fitted with a dough hook. With the mixer on low spead, add the buttermilk mixture and mix until the dough comes together. About 1 minute.
Increase the speed to medium-low and knead until the dough is smooth and stretchy, approximately 10 minutes. Turn the dough out onto a clean surface and knead by hand. Form a smooth, round ball and place the dough into a lightly oiled bowl. Cover loosely with plastic wrap or a damp kitchen towl and let rise in a warm place until the dough has doubled in size. Approximately 2-2 1/2 hours.
Butter a 13×9 inch baking dish and set aside.
Mix the brown sugar, cinnamon, salt and nutmeg in a separate small bowl and set aside.
Turn the dough out onto a lightly floured surface and press the dough into a 16 by 12 inch rectangle. Spread the butter over the entire surface of the dough and then sprinkle the brown sugar mixture over the butter leaving a 3/4 inch border along the top edge. Press down on the sugar mixture to adhere it to the butter.
Spread the peaches evenly over the sugar mixture.
Roll the dough into a tight cylinder being sure to push the butter mixture into the dough so it doesn’t get squeezed out, and press the seam closed. Roll the cylinder onto a lightly floured baking sheet, seam side down. Gently stretch the cylinder until it is 18 inches in length, with an even diameter, and refrigerate for 30 minutes.
Remove from the refrigerator and pat the ends to even them. Slice the dough into 12 evenly sized rolls using a serrated knife. Arrange the rolls, cut side down in the prepared baking dish.
Without pressing on the rolls, wrap the baking dish tightly with greased plastic wrap and refrigerate for up to 16 hours. (You can skip this step if making them the same day.)
Remove the rolls from the refrigerator and remove the plastic wrap. Let them sit at room temperature until puffy and almost doubled in size, approximately 1 hour.
In a small bowl, blend together the powdered sugar, flour and butter with a fork until pea size clumps form. Sprinkle the streusel mixture over the rolls.
Preheat the oven to 350 degrees. Bake for 20-30 minutes or until golden brown. Turn the rolls out onto a wire rack and let cool for 5-10 minutes before icing.
In a small bowl, whisk the powdered sugar, milk and lemon extract together until thick and smooth.
Flip the rolls upright and drizzle the glaze over the rolls evenly.
To freeze: After arranging the rolls in the baking dish, cover loosely with greased plastic wrap and let rise in a warm place until the rolls have doubled in size, approximately 1 hour. Wrap the dish tightly without pressing on the rolls and freeze up to 1 month. To bake, preheat the oven to 350 degrees. Unwrap the rolls and wrap tightly with foil. Bake the rolls for 20 minutes and then remove the foil and continue baking until golden, an additional 30 minutes. Turn out onto a wire rack, cool and ice as directed.