hi -- can any of the steps be done ahead of time?

You could slice the peaches, though you'd want to chill them and that could make for a longer baking time. You could measure out the dry ingredients to save time making the batter. You could likely assemble it ahead just before to the point where you add the sugar and hot water topping, then cover, chill, and bake from frozen, but again it would need to bake longer. Otherwise, it's actually pretty quick to assemble, especially if you can recruit help cutting the peaches! And it will stay warm for a good while, and rewarm in a low oven well if you want to bake it earlier in the day.