Lalla Rookh Pie

Name: Lalla Rookh Pie
Cuisine: European
Ingredients: 6 Tbsp. (3 oz.) unsalted butter, plus more for greasing; 6 oz. English-style digestive biscuits (such as McVitie’s), or substitute graham crackers (about twelve 3-inch biscuits); ½ cup (2 oz.) toasted walnut halves, plus 8 additional walnut halves for garnish; ¼ cup (2 oz.) sugar; Pinch of kosher salt; 1½ qt. store bought vanilla ice cream; ½ cup dark rum or Cognac; 1 cup heavy cream; 2 Tbsp. confectioners’ sugar; 1½ tsp. instant espresso powder dissolved in 2 tsp. heavy cream; ¾ tsp. vanilla extract; Bittersweet chocolate shavings, for garnish