Sheet-Pan Crisp Apple Streusel Bars

Serves 6 · 25 min prep · 42 min cook

Ingredients

• 1 1/2 cups all-purpose flour
• 1 cup old-fashioned oats
• 3/4 cup light brown sugar
• 1/4 cup granulated sugar
• 1 1/2 tsp ground cinnamon
• 3/4 tsp kosher salt
• 12 tbsp unsalted butter, cold and cubed
• 3 medium crisp apples such as Honeycrisp
• 1 tbsp fresh lemon juice
• 1 tbsp cornstarch
• 1 tsp vanilla extract

Instructions

1. 1Preheat the oven to 375°F and line a rimmed quarter-sheet pan or 9-by-13-inch pan with parchment, leaving overhang for easy lifting.
2. 2In a large bowl combine the flour, oats, both sugars, cinnamon, and salt. Add the cold butter cubes and work them in with your fingertips or a pastry cutter until the mixture forms large, sandy clumps and no dry flour remains.
3. 3Press roughly two-thirds of the streusel mixture firmly and evenly into the bottom of the prepared pan to form a compact crust. Bake the crust alone for 12 minutes until it just begins to set and turn pale gold at the edges.
4. 4While the crust bakes, core and thinly slice the apples; toss them immediately with lemon juice, cornstarch, vanilla, and a spoonful of the remaining streusel sugar mixture so they stay bright and the juices thicken later.
5. 5Remove the hot crust from the oven and scatter the apple mixture evenly over it. Crumble the remaining streusel generously over the apples, leaving some larger clumps for texture.
6. 6Return the pan to the oven and bake until the topping is deep golden brown, the apples are tender when pierced, and the juices bubble thickly at the edges, 25 to 30 minutes more.
7. 7Cool the pan on a wire rack for at least 45 minutes so the bars set cleanly. Use the parchment to lift out, then cut into six neat rectangles and serve slightly warm or at room temperature.