Summer Berry Stovetop Crisp

Ingredients

For 6 servings

• •0.75 tasse plus 1 Tbsp. (102 g) whole wheat flour
• •0.75 tasse (67 g) old-fashioned oats
• •0.6666666666666666 tasse plus ½ cup (packed; 233 g) dark brown sugar
• •2.25 c. à café ground cinnamon, divided
• •2.25 c. à café Diamond Crystal or 1¼ tsp. Morton kosher salt, divided
• •8 c. à soupe unsalted butter, divided
• •1.5 c. à café vanilla extract
• •5 c. à café cornstarch
• •Juice of 1 small lemon
• •2 lb mixed fresh berries (such as blueberries, strawberries, and/or blackberries), halved if large

Method

1. 1.Mix ¾ cup plus 1 Tbsp. (102 g) whole wheat flour, ¾ cup (67 g) old-fashioned oats, ⅔ cup (packed; 133 g) dark brown sugar, 2 tsp. ground cinnamon, and 1¼ tsp. Diamond Crystal or ¾ tsp. Morton kosher salt in a medium bowl to combine.
2. 2.Melt 7 Tbsp. unsalted butter in a 9"-diameter cast-iron skillet over medium heat. Drizzle butter over dry ingredients and add 1½ tsp. vanilla extract; mix and squeeze together with your hands to create small clumps. Reserve skillet.
3. 3.Melt remaining 1 Tbsp. unsalted butter in reserved skillet over medium-low heat. Add streusel to pan; reserve bowl. Cook, gently stirring often and breaking up any clumps larger than a marble, until oats are golden and mixture has darkened by a few shades, 8–10 minutes. (Streusel will firm up more as it cools, so don’t worry if it feels a little soft.) Spread out on a rimmed baking sheet or large plate and let cool. Reserve pan.
4. 4.Mix 5 tsp. cornstarch and 2 Tbsp. cold water in a small bowl; set slurry aside.
5. 5.Toss juice of 1 small lemon, 2 lb. mixed fresh berries (such as blueberries, strawberries, and/or blackberries), halved if large, and remaining ½ cup (packed; 100 g) dark brown sugar, 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt, and ¼ tsp. ground cinnamon in reserved bowl. Transfer berries, including any juices in the bottom of the bowl, to reserved pan and cook over medium-high heat, stirring often, just until slightly softened, 5–7 minutes. (Pan will be very full, so stir carefully.) Stir reserved cornstarch slurry if needed, then add to pan. Cook, stirring constantly to combine evenly, until mixture thickens, 30–60 seconds. Let filling cool 5 minutes; scatter streusel over.