Ingredients

• 14 graham crackers (about 8 ounces)
• 2 tablespoons raw sugar or granulated sugar
• 1 tablespoon all-purpose flour
• 1/2 teaspoon kosher salt
• 8 tablespoons (1 stick) unsalted butter, melted, slightly cooled
• 2 cups walnuts
• 4 ounces white chocolate, melted
• 3 large eggs
• 3/4 cup light corn syrup
• 2/3 cup (packed) light brown sugar
• 1/4 cup plus 2 tablespoons barley malt syrup
• 1/4 cup malted milk powder
• 1 tablespoon malt vinegar
• 3/4 teaspoon kosher salt
• 1/2 teaspoon vanilla extract
• 1/4 cup (1/2 stick) unsalted butter
• Unsweetened whipped cream (for serving; optional)

Instructions

1. Place a rack in middle of oven and preheat to 325°F. Pulse graham crackers in a food processor until very fine crumbs form (you should have about 2 cups). Add raw sugar, flour, and salt and pulse to combine. Add butter and pulse until mixture is the consistency of wet sand.
2. Transfer mixture to a 9" pie dish. Using a measuring cup, press firmly onto bottom and up sides of dish. Place pie dish on a rimmed baking sheet and bake crust, rotating halfway through, until dry and set, 20–25 minutes. Transfer pie dish to a wire rack and let crust cool.
3. DO AHEAD: Crust can be baked 1 day ahead. Store wrapped tightly at room temperature.
4. For filling and assembly: Toast walnuts on a rimmed baking sheet (oven should still be at 325°F), tossing occasionally, until slightly darker and fragrant, 8–10 minutes; let cool. Pour white chocolate over cooled crust and, using a small offset spatula or the back of a spoon, spread over bottom and up sides, leaving 1/4" border along edge. Let stand until chocolate is set, 20–25 minutes. Whisk eggs, corn syrup, brown sugar, barley malt syrup, malt powder, vinegar, salt, and vanilla in a medium bowl. Melt butter in a small saucepan over medium heat. Cook, stirring often, until butter foams, then browns (do not let burn), about 5 minutes. Let cool slightly. Whisk brown butter into egg mixture, then fold in walnuts. Place pie dish on a rimmed baking sheet and pour in filling. Bake, rotating halfway through, until set (center should not jiggle), 60–70 minutes. Transfer pie dish to a wire rack and let pie cool. Cover and chill at least 2 hours before slicing. Serve pie topped with whipped cream, if desired. DO AHEAD: Pie can be baked (without whipped cream) 2 days ahead. Keep chilled.
5. Toast walnuts on a rimmed baking sheet (oven should still be at 325°F), tossing occasionally, until slightly darker and fragrant, 8–10 minutes; let cool.
6. Pour white chocolate over cooled crust and, using a small offset spatula or the back of a spoon, spread over bottom and up sides, leaving 1/4" border along edge. Let stand until chocolate is set, 20–25 minutes.
7. Whisk eggs, corn syrup, brown sugar, barley malt syrup, malt powder, vinegar, salt, and vanilla in a medium bowl.
8. Melt butter in a small saucepan over medium heat. Cook, stirring often, until butter foams, then browns (do not let burn), about 5 minutes. Let cool slightly. Whisk brown butter into egg mixture, then fold in walnuts.
9. Place pie dish on a rimmed baking sheet and pour in filling. Bake, rotating halfway through, until set (center should not jiggle), 60–70 minutes. Transfer pie dish to a wire rack and let pie cool. Cover and chill at least 2 hours before slicing.
10. Serve pie topped with whipped cream, if desired.
11. DO AHEAD: Pie can be baked (without whipped cream) 2 days ahead. Keep chilled.