Preheat the oven to 375 F. Generously butter a 10-inch cast-iron skillet or other oven-safe pan.
Make the crisp topping
In the bowl of a food processor, combine the whole wheat flour, brown sugar, almond meal, cinnamon, baking powder, baking soda, and kosher salt and pulse a few times to combine. Add the butter. Pulse 20-30 seconds, or until the mixture resembles coarse cornmeal. Slowly add the buttermilk and continue pulsing until the liquid is incorporated. At this point, the dough should come in clumps.
Turn the topping out into a medium bowl and fold in the Uncle Sam cereal and almonds; mix with a wooden spoon (or your hands) until both are incorporated.
Prepare the filling
Toss together the cherries, sugar, lemon juice, vanilla extract and cornstarch in a medium mixing bowl. Transfer to the prepared cast iron skillet or other baking-safe pan.
Spoon the topping over the cherries by the heaping tablespoon, so they’re almost fully covered (it’s okay if some around the edges are peeking through). Place in the oven and bake for about 30 minutes, rotating the pan halfway through to ensure even baking. The top should be golden brown and the cherry juices bubbling through.
Remove from the oven, and cool for at least 20 minutes before serving. Serve warm or room temperature. Wrapped in plastic wrap, the crisp will keep at room temperature for 1 additional day.