Mix together flour, brown sugar, baking powder, baking soda, and salt in a large bowl. Grate in butter. Mix together the buttermilk and pumpkin puree. Add to flour-butter mixture until a dough forms, being careful not to overwork.
Drop biscuits onto greased cookie sheet in 6 equal portions.
Let biscuits cool and store in an air tight container.
For the Breakfast Sandwich...
In a non-stick frying pan, fry the sausage for 2-4 minutes per side. Set aside. Fry eggs to desired doneness. Re-warm the biscuits.
Split biscuits. Assemble the sandwich by placing the spinach on the bottom biscuit and then layering with the sausage, then egg and finally the red pepper cream cheese spread.
Notes
I like my fried eggs with a bit of a runny yolk. That said, if you are making these sandwiches to eat on the trail, that can create a bit of a mess, and you may want to consider a harder cook.