Heat oven to 425 F/220 C. Grease cake pans generously, and line bottoms with a circle of parchment paper.
Combine flour, baking soda, baking powder, salt, cinnamon and nutmeg together in a large bowl. Set aside.
Beat together brown sugar and shortening until light, either in the bowl of a standing mixer or by hand.
Incorporate eggs one at a time. Add vanilla extract.
Alternate adding buttermilk and dry ingredients to mixture. Beat after each addition until just combined.
This will produce a dough rather than a batter. Divide dough into seven equal portions. Tip: if you have a kitchen scale handy, weigh the dough. Divide that number by 7. It will save you some guess work.
With lightly floured hands, pat dough into baking pans. It might take a little bit of effort. Layers will be very thin.
Bake each layer for about 10 minutes, until lightly golden and springs gently to the touch. Allow to cool about 15 minutes, and then very gently remove the cake from the pans. This can be a little tricky. If you try to remove them while still very hot, they are a little too fragile and can easily break. If you wait too long, they're harder to get out. Waiting 15 minutes seems to be just right. Once cakes are out of the pans, allow to cool on a wire rack until they can easily be handled (they will sort of feel like cookies once cooled).