Blondies may well have been the original brownies--although the exact details of culinary history are pretty smeared at this point. Still, it's thought that this delicate cake with chocolate bits may have been the precursor to its more chocolate-y cohort.
We'd like to give you some tips about baking as we go along, so let's just get right to this terrific recipe.
First, set the rack in the center of the oven and fire the oven up to 350F (175C). Put a little butter on a wadded-up piece of paper towel or wax paper and grease the inside of a 9 x 13-inch (23 x 33-cm) metal baking pan. (We found a glass baking pan superheats both the goat cheese and chocolate to give them a bitter edge, even if we lowered the oven temperature.) Add a bit of flour and knock it around the inside of the pan until you've coated the whole thing. Shake out any excess in the sink. (And if you see dry spots lacking butter to hold the flour, grease these up and repeat the flour trick.)
Next, whisk the dry ingredients in a bowl: 2 cups (240 grams) all-purpose flour, 1 teaspoon baking powder, and 1/2 teaspoon salt.
Now it's the mixer's turn. Beat 8 ounces chilled (225 grams) fresh chèvre or soft goat cheese, 8 tablespoons (120 grams) chilled but chunked unsalted butter, 1 cup (200 grams) granulated sugar, and 1 cup (180 grams) packed dark brown sugar in a large bowl with an electric mixer at medium speed until light, even fluffy, about 8 minutes, maybe more.
Seriously. At least eight minutes. I left the mixer going and went upstairs and put the clothes in the dryer. I came back downstairs, scraped down the inside of the bowl, and let it go some more.
At the end, the mixture looks slightly "broken" with little grains throughout, not of sugar, but of the sugar liquefying and reforming other combinations. You want air. Lots of air.
After that, beat in 2 large eggs one at a time, then beat in 1 large egg yolk and 1 tablespoon (15 ml) vanilla extract.
Scrape down and remove the beaters. Use a rubber spatula to fold in the flour mixture, just until it begins to disappear and get evenly distributed in the batter.
Note this picture. We don't want to stretch the wheat glutens in any way. So just as the flour starts to get mixed throughout but is still somewhat visible, fold in 1 1/2 cups (340 grams) dark chocolate chips. I used 66% cocoa chips. You could even go a little darker.
Scrape and spread the batter into the prepared pan. It's sticky, so you might want to dollop it all around the pan, then gently press it into place with washed fingers. Don't press out that air!
Bake until lightly browned, until a toothpick inserted into the center of the cake some out with a few moist crumbs, 40 to 45 minutes. Cool in the baking dish on a wire rack for 10 minutes before cutting into squares--which can be saved a couple days in a sealed container at room temperature or frozen between sheets of wax paper in a sealed container for several months. It's full of goaty goodness--these wonderful little savory, salty, umami notes in the otherwise tender, sweet cake.