Saltine Cracker Brownie Ice Cream Sandwich

Name: Saltine Cracker Brownie Ice Cream Sandwich
Ingredients: Cracker and Brownie Layers; 60 salted saltines or soda crackers; 2 tablespoons unsalted butter for brushing; 90 grams of semi-sweet chocolate chips; 113 grams of unsalted butter; 1/2 cup granulated sugar; 1/2 cup brown sugar; 2 large eggs; 1 1/2 tablespoons ground espresso beans; 1 teaspoon vanilla extract; 2/3 cup all purpose flour; 2 tablespoons cocoa powder; 1/2 teaspoon fine sea salt; No churn ice cream layer (adapted from Martha Stewart); 240 grams of sweetened condensed milk; 1 1/3 teaspoons pure vanilla extract; 1 1/2 tablespoons dark rum; 1 1/3 cups heavy cream