Cheesecake Marble Brownies

Last night there was a Relief Society activity at our President's parents' condo in Midway. I used the occasion as an excuse to make something delicious. I decided on the cheesecake-swirled brownies from Smitten Kitchen, that she adapted from Gourmet. I didn't really change the recipe much except that I used a little more chocolate than she says to use because a)I love chocolate, b)you can never have too much of it, and c)the bar was 4 oz and I figured hey-what's-another-ounce.
Anyway, they were a big hit at the party (so big, in fact, they were used as ammunition in a pseudo-food fight) and were very moist and rich and just so incredibly yummy. And for some reason everyone was really impressed that I'd made them from scratch.

Cheescake Marble Brownies
from Smitten Kitchen

Makes 16 2-inch square, thick brownies (or a lot more if people keep cutting them into tinier pieces because they just know it's going to go straight to their thighs)

Brownie batter
1 stick (1/2 cup or 4 ounces) unsalted butter, cut into pieces
3 (no, 4!) ounces unsweetened chocolate, chopped
1 cup sugar
2 large eggs
1/2 teaspoon pure vanilla extract
2/3 cup all-purpose flour

Cheesecake batter
8 ounces cream cheese, well softened (I left mine out for a while, but I didn't realize it still wasn't soft enough until after I'd added the egg, so rather than risk cooking the egg by microwaving it, I just turned the heat back on on the pot of water I was using for the double boiler and warmed it up more gently that way)
1/3 cup sugar
1 large egg yolk
1/4 teaspoon pure vanilla extract

Plus
1/2 cup semisweet chocolate chips (both Smitten and myself put the chips on top, but I only did it because I forgot I wanted to put them in the cream cheese batter. She did it because she thought it would mess up the swirling. You may do as you please.)

Make brownie batter:
Put oven rack in middle position and preheat oven to 350°F. Grease an 8-inch square baking pan. Heat butter and chocolate in a 3-quart heavy saucepan — though I did mine double-boiler style, placing the mixing bowl I was using over simmering water, thereby creating one less dirty dish and melting the chocolate more gently (What I did was just mix my batter in the saucepan and not even worry about a bowl) — over moderately low heat, whisking (or forking if you have no whisk) occasionally, just until melted. Remove from heat and whisk in sugar, eggs, vanilla, and a pinch of salt until well combined. Whisk in flour until just combined and spread in baking pan.

Make cheesecake batter:
Whisk (although I found a spoon actually worked better to get all the lumps out) together cheesecake batter ingredients in a small bowl until smooth. Dollop over brownie batter, then swirl in with a butter knife. (Here I had some problems, possibly because my cream cheese hadn't been all that soft. The cheesecake batter wanted to swirl in clumps. I ended up pulling some of the brownie batter over the cheesecake batter in order to get rid of some of the humongous white blobs, and this allowed the cheesecake to infiltrate below the top layer, which is totally fine, but perhaps does not look as pretty.)

Sprinkle chocolate chips over cheesecake/brownie batter swirl. (If you didn't already put them in the batter.)

Bake brownies:
Bake until edges are slightly puffed and center is just set, about 35 minutes. Serve warm or at room temperature. (Warning: it took almost 2 hours to completely cool at room temperature, so if you're on a tight schedule, I'd suggest putting them in the fridge or freezer-- but be aware that something incredibly hot in the freezer will definitely start to defrost some things, so maybe wait until it's partly cooled first.)

P.S. I'm really sorry I didn't take any pictures; I'd completely forgotten until I was walking to my car. Smitten has some on her website if you're the type who needs to see what the end product looks like.