This peach crumb bars recipe is a cross between peach pie and peach crisp, combining a warmly-spiced fruit filling with a buttery brown sugar-oat crust in portable dessert bar form.
Add the peaches, sugar, and salt to a medium saucepan over medium heat. Cover the saucepan and cook until the peaches are soft and jammy, about 7 to 10 minutes, stirring occasionally. Turn the heat down to medium-low, stir in the lemon juice, cinnamon, nutmeg, and cornstarch slurry. Cook until the mixture thickens, about 30 seconds, stirring constantly.
Set aside to cool while you make the crust. (TIP: The peach filling will be like a cross between jam (but not as sweet) and peach pie filling (but not as syrupy).)
Make the Top and Bottom Crust:
Use a hand-held electric mixer to cream together the butter, brown sugar, and vanilla in a large bowl. Add the flour, oats, cornstarch, and salt, and beat just until combined. Stir in the nuts.
Assemble and Bake:
Prep. Preheat the oven to 350F. Line an 8.5 by 4.5-inch loaf pan (or equivalent) with a piece of parchment paper so it hangs over all 4 sides.
Assemble. Press about half of the dough evenly into the bottom of the prepared pan. Spread the peach filling evenly onto the dough. Crumble the remaining dough on top of the filling. Sprinkle 1 tablespoon oats on top.
Bake and cool. Bake until the top is golden brown, about 50 minutes. Cool completely (about 2 hours) before icing.
Make the Icing:
Add all ingredients to a small bow and whisk to combine. Drizzle the icing on top of the cooled bars.
Let the icing set before slicing and serving.
Notes
Loaf Pan Size: A 9 by 5-inch loaf pan will also work here; just check for doneness around the 40 to 45-minute mark, as they will be a bit thinner.
Storage: After slicing, you can store these bars in a covered container at room temperature for up to 3 days, in the fridge for up to 1 week, or in the freezer for up to 3 months.