Preheat the oven to 350 degrees and grease an 8×8 inch pan (or a dish of similar size).
In a large bowl, mix all of the filling ingredients together then pour into the greased baking dish and spread evenly.
Place the pecans and walnuts into a food processor and pulse until finely chopped.
Add in the remaining filling ingredients and pulse until well combined and sticky.
Crumble the topping over the peach filling in a thick layer.
Bake for 30-40 minutes (the smaller the pan, the deeper the filling and the longer it will take) until the peaches are bubbling and the topping is golden brown. If the topping starts to get too dark, cover with foil until baking is complete.
Remove and let cool for about 10 minutes before serving. Serve alone or topped with ice cream or whipped cream (I use dairy free of course)
Notes
Leftovers: Store in a sealed container in the fridge for up to 3 days. To serve, you can heat in the microwave or pop in the oven for a bit to get the top crispy again.