Preheat the oven to 325 degrees
Line baking sheet with parchment paper
Place cashews in food processor and process for 10 seconds, until ground course
Add the eggs, vinegar, milk, and coconut oil and process until smooth, about 30 seconds
Add flours, salt, and baking soda and process again until smooth, sticky dough has formed
Using wet hands, shape the dough into 4 buns
Place the egg yolk and 2 tsp. almond milk in a small bowl and whisk
Brush dough with the egg wash and sprinkle with seeds
Place buns on a baking sheet and bake for 25 minutes