Ingredients
Scale
- 1/2 cup (115 grams) unsalted butter
- Scant 1 teaspoon kosher salt
- 1 cup (200 grams) lightly packed light brown sugar
- 3 tablespoons whole milk
- 1 large egg
- 2 teaspoons vanilla extract
- 1 teaspoon baking powder
- 1 cup (127 grams) all-purpose flour
- 1/4 cup rainbow jimmies, plus 1 tablespoon to top the blondies and 2 tablespoons to sprinkle on the ice cream, plus more for dipping (though that’s optional – more is more here!)
- 1 pint vanilla ice cream
- 1 pint strawberry ice cream
Instructions
- Place a rack in the upper third of the oven and preheat oven to 325 degrees F.
- Lightly spray the bottom of a 9×13-inch cake pan with nonstick cooking spray. Line the bottom of the pan with parchment paper. Lightly spray the parchment paper and the sides of the pan with nonstick cooking spray.
- In a large bowl, melt the butter until just melted but not incredibly hot. If the butter is hot, it will cook the egg, so let the butter rest if it’s become quite hot while melting. Add the salt, brown sugar, milk, egg, and vanilla extract and whisk until the mixture is smooth.
- Sprinkle the batter with baking powder and stir to combine. Stir in the flour and 1/4 cup of rainbow sprinkles.
- Spoon the batter into the prepared pan in small dollops. Spread edge to edge in a thin, even layer using a small offset spatula. Sprinkle the top with 1 tablespoon of rainbow sprinkles.
- Bake for 15 minutes until the blondie is set but still soft. Remove from the oven and let cool completely in the pan. You can transfer the pan to the freezer to cool quickly, in about 20 minutes. Additionally, if your ice cream is rock-hard, transfer it to the refrigerator for 15-20 minutes so it’s easier to scoop.
- Once the blondie is cold to the touch, run a knife around the edges of the pan to loosen. Use the parchment paper to slide the blondie from the pan and cut in half widthwise. Return the used parchment to the pan so that it covers the bottom of the left side of the pan and then drapes over the left edge. We’ll use the parchment to help shape the sandwiches. Place half of the blondie you just cut on top of the parchment paper inside the pan, upside down. Scoop the ice cream in small scoops, alternating vanilla and strawberry across the blondie. Sprinkle with 2 tablespoons of sprinkles and use the offset spatula to quickly press the ice cream into an even layer. Press the second blondie half, right side up, onto the ice cream, using the hanging parchment to help press the blondie down. Place the pan in the freezer.
- Freeze for 6 hours, though overnight is best.
- Once the ice cream is fully solid, remove the blondie ice cream slab to a cutting board and cut into twelve 2-inch squares. Dip one side in colored sprinkles if you’d like and return to the freezer until just ready to serve.