For the crust: Combine the pretzels, graham crackers, sugar, a pinch of salt and the melted butter in a large bowl. Press the crust into the bottom of a 13-by-9-inch clear glass baking dish. Set aside while you make the filling.
For the filling: In the bowl of a mixer fitted with a paddle attachment, cream the softened cream cheese on medium speed, scraping down the sides of the bowl and the beater often, until smooth and creamy, 2 to 3 minutes. Add the sour cream and sugar and continue to mix until combined, 1 to 2 minutes. With the mixer speed on low, add the eggs one at a time, thoroughly mixing after each addition. Mix in the vanilla. Pour the filling over the crust and bake until the center is no longer jiggly, about 1 hour. Let the cheesecake sit at room temperature for at least 1 hour.
Meanwhile, melt the strawberry preserves in a small saucepot over low heat. If you prefer no seeds, use a fine mesh sieve to strain it into another bowl. Pour the melted preserves over top of the cheesecake and smooth it out into an even layer. Let the cheesecake cool at room temperature for another 30 minutes to 1 hour, then slice into 24 squares while still warm. Refrigerate until chilled completely, at least 4 hours or up to overnight.