Preheat the oven to 325 F.
Make topping first. Mix chopped nuts, 1 tbsp maple syrup, melted coconut oil, sea salt in a medium bowl.
Spread out on a baking sheet and bake about 10 minutes. Nuts should be light golden brown. When the nuts are done set the over to 350 F.
While nuts are baking, make the apple base. Using a soup pot, add diced apple, lemon zest and juice, 3 tbsp maple syrup and cinnamon.
Bring to a boil over medium heat, stirring every few minutes until the apples have softened.
When apples have softened, remove from heat and mix in almond flour and flaxseeds.
Transfer to a baking dish. Add nut topping.
Bake about 35 minutes until the top is golden brown. Cover with foil if you're worried about burning the nut topping.
Serve in individual dishes.