Preheat the oven to 350 degrees. Grease an 8x8-inch baking dish with cooking spray or oil.
Add the dates and 1/2 cup of water to a small saucepan. Heat over medium-high heat. Let boil until the water is completely evaporated, about 10 minutes.
Meanwhile, combine the flours, spices, salt, baking powder and baking soda in a large mixing bowl.
Add the soaked dates and milk to a food processor or blender and blend until smooth.
In a separate large bowl, combine the blended dates, pumpkin puree, oil, maple syrup and vanilla. Whisk until well combined and smooth.
Add the wet ingredients to the bowl of dry ingredients and, using a rubber spatula, gently fold together until well combined.
Pour the mixture into your greased 8x8 baking dish and spread in a single layer. Top with a pinch of flaky sea salt (if desired) and transfer to the oven.
Bake for 30-35 minutes, until a toothpick inserted into the center comes out clean and the top is light golden brown.
