Directions

• Step 1Preheat oven to 350º. Grease an 8"-by-8" baking pan with cooking spray and line with parchment, leaving an overhang on 2 opposite sides.
• Step 2In a large bowl, whisk brown sugar, butter, and granulated sugar until well combined. Whisk in eggs, vanilla, and salt to blend. Stir in flour until just combined.
• Step 3Spread 1 1/2 cups batter in bottom of prepared pan. Top with dollops of jam, then gently spread jam over batter with an offset spatula or the back of a spoon.
• Step 4Dollop remaining batter over jam. Using offset spatula or the back of a spoon, gently smooth batter in an even layer, being careful not to disturb jam layer. (The goal is to trap the jam in the middle, like a Pop-Tart.)
• Step 5Bake blondies, tenting with foil if darkening too quickly, until golden around the edges and a tester inserted into the center comes out with a few moist crumbs attached, 45 to 50 minutes. Let cool in pan 15 minutes, then lift out of pan using parchment overhang and transfer blondies to a wire rack. Let cool completely.
• Step 6In a medium bowl, whisk powdered sugar and 1 tablespoon milk until smooth, adding more milk by the 1/2 teaspoonful until glaze is thick yet pourable.
• Step 7Pour glaze over cooled blondies and spread with offset spatula. Top with sprinkles. Let glaze rest until set, about 1 hour.