Preheat and prep the pan: Heat the oven to 350°F (175°C). Line an 8x8-inch or 9x9-inch pan with parchment, leaving overhang for easy lifting. Lightly grease the parchment.

Prep the apples: Peel (if you like), core, and dice 2 medium apples into small cubes (about 1/4–1/2 inch). You want around 1½–2 cups. Pat dry with a paper towel to remove excess moisture.

Melt the butter: In a medium saucepan or microwave-safe bowl, melt 1/2 cup (1 stick/113 g) unsalted butter. Let it cool for 3–4 minutes so it doesn’t scramble the eggs.

Whisk the wet ingredients: In a large bowl, whisk the melted butter with 3/4 cup packed brown sugar and 1/4 cup granulated sugar until glossy. Whisk in 2 large eggs, one at a time, then 2 teaspoons vanilla.

Combine the dry ingredients: In a separate bowl, whisk 1 cup plus 2 tablespoons all-purpose flour, 1 teaspoon baking powder, 1/2 teaspoon fine sea salt, and 1 teaspoon ground cinnamon.

Make the batter: Stir the dry ingredients into the wet with a spatula until just combined. The batter will be thick. Fold in the diced apples and, if using, 1/2 cup chopped pecans or 1/3 cup white chocolate chips.

Layer with caramel: Spread half the batter into the pan. Warm 1/3–1/2 cup salted caramel sauce until just pourable. Drizzle half of it over the batter, avoiding the edges. Dollop the remaining batter on top and gently spread. Swirl in the remaining caramel with a butter knife for ribbons.

Bake: Bake for 28–35 minutes, depending on pan size and apple juiciness. The blondies are done when the edges are set, the top is golden, and a toothpick comes out with a few moist crumbs (not wet batter). Do not overbake; they’ll firm up as they cool.

Finish and cool: Immediately sprinkle with a pinch of flaky sea salt. Cool in the pan for at least 45–60 minutes, then lift out and cut into squares. For the neatest slices, chill for 30 minutes before cutting.

Optional serving: Warm a square for 10–15 seconds and top with a scoop of vanilla ice cream and an extra drizzle of caramel.