To make the biscuits, preheat the oven to 400 degrees F. Line a baking sheet with parchment paper or a silicone baking mat and set aside.
In the bowl of a food processor, combine the flour, sugar, baking powder, salt and baking soda, pulsing a few times to mix.Add the butter and pulse until it’s the size of small peas. Pour in the milk, pulsing, until incorporated. Pulse 5 more times, then transfer the dough to a lightly floured work surface. Form dough into a ball, ensuring it is well mixed, sprinkling with flour as needed. Roll the dough out to 1 1/4-inch thick, then use a 2 1/2-inch biscuit cutter to make 8 biscuits, re-kneading and re-rolling the scraps as necessary.
Arrange the biscuits on the prepared baking sheet and bake until lightly browned, 12 to 14 minutes.
Meanwhile, make the gravy: In a large bowl, combine the pork, brown sugar, maple seasoning (if using), salt, black pepper, sage, rosemary, thyme, marjoram, nutmeg and cayenne, stirring to thoroughly combine. Set aside.
In a large skillet over medium heat, warm the oil. Add the onion and cook, stirring occasionally, for 5 minutes. Add the pork mixture and cook, breaking it up with a spoon or spatula, until no longer pink, 5 to 6 minutes. Sprinkle in the flour and cook, stirring, for 1 minute. Stir in the milk, increase the heat to medium high, to bubble and thicken gravy. Reduce heat immediately to bring to a gentle simmer, whisking to smooth any lumps, until completely thickened, 2 to 3 minutes. Add more flour as needed to achieve desired consistency. Remove from the heat and stir in the maple syrup. Taste and adjust seasonings, adding more maple syrup, salt and black pepper to taste.
Split the biscuits and arrange on plates. Spoon the gravy on top and serve.