In a food processor or blender, process graham crackers until very fine. Add butter and brown sugar, processing to combine.
Spray the cups of one 24-cup (or two 12-cup) mini muffin tin generously with nonstick spray. Spoon a heaping teaspoon of graham cracker mixture into each cup. Press down firmly with a flat-bottomed shot glass to form the crust. While making the filling, place muffin tin(s) into refrigerator to chill.
For the filling and garnish:
In a large bowl, beat together softened cream cheese, sweetened condensed milk, and egg beaters until smooth and creamy, about 2 minutes. In a small bowl, whisk together powdered gelatin and boiling water until dissolved. Let cool for 2 minutes (no longer – this is crucial), then add into the cream cheese mixture along with lemon zest and juice. Beat until fully combined.
Fill each mini muffin tin cup with a heaping tablespoon of filling, right to the top. Place filled muffin tins into the refrigerator to firm up, at least 8 hours or overnight.
To remove chilled bites, run a blunt knife around the outside of each cup to pop it out. Top with half a strawberry, sliced in half or thin slices, as you prefer. Store in the refrigerator in an airtight container, up to 5 days. Freeze for up to 3 weeks.