This subtly sweet yeasted cake topped with fresh peaches is a Baltimore staple. Martha made this recipe on episode 702 of Martha Bakes.
Combine 1 teaspoon sugar and milk in a glass measuring cup. Sprinkle yeast over milk and let stand until foamy, about 5 minutes. Add egg and whisk to combine.
Whisk together flour, salt, and remaining 1 tablespoon plus 2 teaspoons sugar in the bowl of an electric mixer. Place bowl on mixer fitted with the dough hook. Add milk mixture to flour mixture and beat to combine. Knead dough for 5 minutes. Add butter, piece by piece, and continue to knead until dough is smooth, about 5 minutes. Transfer dough to a buttered bowl, cover with plastic wrap, and set aside in a warm place until doubled in bulk, about 1 hour.
Punch down dough and remove from bowl. Pat dough into a buttered 13-by-9 1/2-inch rimmed baking sheet. Cover with plastic wrap and let rise for 1 hour.
Preheat oven to 350 degrees. Arrange peaches on dough in a slightly overlapping pattern and sprinkle with sanding sugar. Bake until golden brown and set in the center, 40 to 45 minutes. Brush peaches with jelly. Let cool in pan on a wire rack for 15 minutes, then remove from pan and cool completely on wire rack.