I always start by lining my muffin tin with paper liners since it makes cleanup and removal so much easier. Preheat your oven to 325°F while you get everything else ready. This step takes barely a minute but saves a lot of frustration later.
Combine the graham cracker crumbs, sugar, and melted butter in a bowl until the texture looks like wet sand. Press about a tablespoon of this mixture firmly into the bottom of each liner. I use the back of a spoon to pack it down evenly.
Pop the muffin tin into the oven and bake the crusts for about 5 minutes. This little step firms them up so they don't turn soggy once the wet filling goes on top. Let them cool slightly while you make the filling.
In a large bowl, beat the softened cream cheese until it's completely smooth and lump-free. This usually takes about 2 minutes on medium speed. Scrape down the sides of the bowl so nothing gets left behind.
Mix in the brown sugar, granulated sugar, and pumpkin puree until fully combined. The mixture should look creamy and uniform in color. Don't rush this part, as a smooth base means a smoother finished bite.
Add the eggs one at a time, beating gently after each addition. Stir in the vanilla, pumpkin pie spice, and salt last. Mixing on low speed here helps avoid adding too much air, which can cause cracks.
Spoon or pipe the filling over each pre-baked crust, filling each liner almost to the top. I like using a piping bag for neat, even portions, but a spoon works just as well.
Bake for 18-20 minutes, or until the centers are just slightly jiggly. They'll continue to set as they cool, so don't wait for them to look completely firm in the oven.
Let the bites cool at room temperature for about 30 minutes, then transfer them to the fridge for at least 3 hours. Chilling is what gives them that dense, creamy cheesecake texture.