In New Zealand, these shortbread bars are actually baked throughout the year, but the sheer extravagance of their double-layered topping — rich caramel and a crumbly butter streusel — makes them a perfect holiday treat.
- 20 tbsp. unsalted butter, softened, plus more for pan
- 2 1⁄2 cups flour, plus more for pan
- 1⁄2 cup sugar
- 1 tsp. vanilla extract
- 1⁄4 tsp. kosher salt
- 1⁄4 cup packed dark brown sugar
- 1 tbsp. light corn syrup
- 1 (14-oz.) can sweetened condensed milk
- Heat oven to 350°. Line a 9″ x 13″ baking sheet with parchment paper; grease and flour. In a mixer fitted with a paddle, beat together 16 tbsp. butter, sugar, vanilla, and salt until fluffy. Add 2 1⁄4 cups flour; mix. Transfer 3⁄4 dough to pan; press into bottom; chill. Rub remaining dough and flour into large crumbles; set aside. Combine remaining butter, brown sugar, syrup, and milk in a 2-qt. saucepan. Cook, stirring, over medium-high heat to make caramel, 8–10 minutes. Pour over dough; scatter crumbles over top. Bake until golden, 25–30 minutes. Let cool. Cut into bars.