Preheat your oven to 350°F (175°C). Line an 8x8-inch baking pan with parchment paper.

In a large mixing bowl, whisk together the brown sugar and melted butter until smooth.

Add the vanilla and egg, whisking until combined.

Stir in the sourdough discard until fully incorporated.

Add the flour, baking powder, and sea salt. Mix gently until just combined—do not overmix.

Fold in the chocolate chips, reserving a handful to sprinkle on top.

Pour the batter into the prepared pan and smooth the top. Sprinkle with the reserved chocolate chips.

Bake for 20–25 minutes, or until the edges are golden brown and a toothpick inserted in the center comes out with a few moist crumbs.

Allow the blondies to cool completely in the pan before lifting them out with the parchment and cutting into squares.