Arrange 6 clean 8-ounce glass jars on the counter so the layers can be divided evenly. Leave enough room at the top for the cherry topping and a comfortable spoonful.

Stir the graham cracker crumbs, sugar, melted butter, and salt together in a medium bowl, then add 1/4 cup of crumbs to each jar and press firmly with the back of a spoon. The crumb layer should feel compact and push back slightly against the spoon rather than shifting loosely.

Beat the cream cheese and 2 tablespoons granulated sugar in a large bowl with an electric mixer until fluffy and lump-free, then mix in the condensed milk, sour cream, lemon juice, and vanilla. Stop when the filling looks thick, smooth, and uniform, without streaks of cream cheese.

Divide 1/3 cup of filling among the jars, covering the crust in an even layer, then refrigerate the jars while making the topping. The chilled filling will hold its shape better when the fruit is added later.

Cook the cherries, 1/4 cup granulated sugar, lemon juice, and lemon zest in a large pot over medium-high heat until boiling, then lower the heat to medium-low and stir often for about 8 minutes. The cherries should soften and release deep red juice while still keeping some of their shape.

Whisk the cornstarch and water in a small bowl, stir the slurry into the cherries, and simmer for 2 to 3 minutes before removing the pot from the heat and stirring in the extract. The syrup is ready when it turns clear and glossy and coats the spoon instead of running off like juice.

Cool the cherry topping completely, then spoon about 2 tablespoons over each chilled cheesecake layer. Cool topping protects the cream cheese layer from softening or melting at the edges.

Refrigerate the jars for at least 2 hours before serving them chilled. The filling should look settled and hold a clean line against the glass when you scoop into it.