Line two standard 12 count muffin pans with cupcake liners. Make sure you have room in your refrigerator for both pans. (You refrigerate them in step 6.) Prepare the crust: If your graham crackers aren’t crumbs yet, use a food processor to pulse them into fine crumbs. Pour crumbs into a medium bowl and stir in the brown sugar and melted butter until combined. Mixture will have the consistency of wet sand. Spoon 1 and 1/2 Tablespoons of the crust mixture into each cupcake liner and use the back of the spoon to pack it down tightly.
The next step is optional. Though it’s not required, I recommend baking the crusts for a quick 5 minutes in a 350°F (177°C) oven. The crusts are a little sturdier this way. However, if you can’t use an oven or simply don’t want to, you can skip this step. The crust will just be a bit crumblier. If baking, let the warm crusts cool for 10 minutes before adding the filling on top.
Make the filling: Using a hand mixer or a stand mixer fitted with a whisk attachment, whip the cold heavy cream into stiff peaks on medium-high speed, about 3 minutes. Set aside. Using a hand mixer or a stand mixer fitted with a whisk or paddle attachment, beat the cream cheese and granulated sugar together on medium speed until smooth and creamy. Scrape down the sides and up the bottom of the bowl with a silicone spatula as needed. Add the sour cream, lemon juice, and vanilla extract. Beat on medium-high speed until smooth and combined, about 1 minute. Make sure there are no large lumps of cream cheese. If there are lumps, keep beating until smooth. Using your mixer on low speed or a silicone spatula, fold the whipped cream into the cheesecake filling until combined. This takes several turns of your rubber spatula. Combine slowly as you don’t want to deflate all the air in the whipped cream.
You can use a spoon or piping bag to transfer the filling on top of the crusts. Spoon or pipe about 2 Tablespoons of filling over each crust. I prefer piping the filling because it’s a little easier and neater. Fit your piping bag with a large star or round piping tip, then transfer the filling to the bag and pipe. (You could also use a plastic zipped-top bag. Spoon the filling inside, snip an end off a corner, and pipe.) Use the back of a spoon to smooth the tops so they are flat.
Refrigerate the mini cheesecakes in the pans for at least 3 hours and up to 2 days. If refrigerating for longer than 3 hours, I recommend covering with aluminum foil or plastic wrap.
Keep refrigerated until ready to serve. Serve with optional toppings (see recipe Note). The cheesecakes begin to soften and stick to the liners after about 30–60 minutes at room temperature.
Cover and store leftover mini cheesecakes in the refrigerator for up to 5 days.
