I’d rather have ice cream toppings than ice cream, and the blondies focus on two favorite toppings. They’re fast, easy, and are made in one bowl, without a mixer. They’re soft, dense, moist, and the butter and brown sugar caramelize while baking. Along with the salted caramel swirls, there’s plenty of bold caramel flavor. Don’t get carried away with swirling the hot fudge and caramel because they spread while baking and over-doing it causes the swirls to bake together, and the top will look muddy and messy. The hot fudge and caramel will be glistening, shiny, and stay wet-looking, so make sure you’re evaluating the blondie base, not the toppings, in a toothpick test.
Preheat oven to 350F. Line an 8-by-8-inch baking pan with aluminum foil, spray with cooking spray; set aside.
In a large, microwave-safe bowl melt the butter, about 1 minute on high power.
Wait momentarily before adding the egg so you don’t scramble it. Add the egg, brown sugar, vanilla, and whisk until smooth.
Add the flour, optional salt, and stir until just combined; don’t overmix.
Turn batter out into prepared pan, smoothing the top lightly with a spatula.
Evenly drizzle the hot fudge over the top.
Evenly drizzle the salted caramel over the top.
With the tip of a table knife, lightly swirl the hot fudge and caramel into the batter. Don’t overdo the swirling because the hot fudge spreads and widens as it bakes, and if you overdo the swirling, the surface will look blackened and messy post-baking. It’s okay to leave some fairly bare and unswirled patches.
Bake for about 25 to 30 minutes, or until a toothpick inserted in the center (if you can find a bare patch to test) comes out mostly clean, or with a few moist crumbs, but no batter. The hot fudge and caramel will be glistening, shiny, and stay wet-looking, so make sure you’re evaluating the blondie base, not the toppings, if you do a toothpick test. Allow bars to cool in pan for at least 30 minutes before slicing and serving. Bars will keep airtight at room temperature for up to 1 week, or in the freezer for up to 6 months.