For this recipe, err on the side of under rather than overdone. As soon as the top of the brownie looks dry, press your finger lightly in the center; it should feel like Jell-O under the surface.

2 large eggs. 1/2 teaspoon vanilla extract. 6 tablespoons (50 grams) all-purpose flour. 1/4 teaspoon salt. 3/4 cup (100 grams) walnuts or pecans, toasted, chopped; see cook’s notes ...