Warm Chocolate-Chunk Blondie Bars

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Warm Chocolate-Chunk Blondie Bars

star rating (9) rate this recipe »
Published prior to 2008

Ice cream and summer go hand in hand like... well, like ice cream and summer! There's no happier marriage. When you get tired of ice cream in a dish, or even in a fancy waffle cone, try plopping it atop one of these moist, chewy, chocolate-studded "blondie" bars, which you've warmed briefly in the toaster or microwave. Ice cream melting atop warm chocolate... now that's MY idea of comfort food!

2/3 cup (1 1/3 sticks, 5 1/4 ounces) unsalted butter, melted
1 pound (2 cups, firmly packed) brown sugar, light or dark
1/4 cup (1 3/4 ounces) granulated sugar
1/2 teaspoon salt
1 tablespoon (1/2 ounce) vinegar, white or cider
3 large eggs
1 teaspoon espresso powder (optional)
2 teaspoons vanilla
2 1/2 teaspoons baking powder
2 3/4 cups (11 1/2 ounces) King Arthur Unbleached All-Purpose Flour or King Arthur White Whole Wheat Flour
1 3/4 cups (8 ounces) chocolate chunks or 2 cups (12 ounces) chocolate chips
2 cups (about 8 ounces) coarsely chopped nuts (pecans, walnuts, or almonds)

Preheat the oven to 350°F. Lightly grease a 10" x 15" jelly roll pan or 9" x 13" pan.

Combine the butter, sugars, salt, and vinegar, stirring to combine. If the mixture is super-hot from the melted butter, let it cool to lukewarm. Add the eggs, espresso powder, vanilla, and baking powder, beating well. Stir in the flour, mixing thoroughly, then the chocolate chunks and nuts.

Scoop the batter into the prepared pan, using your wet fingers to smooth the top. Bake the bars for 30 minutes (for the jelly roll pan), or about 38 minutes (for the 9" x 13" pan), until the top is golden and shiny, and the center is just barely baked through. Use the sharp tip of a knife to peek into the center; it should be very damp, but not unbaked. Yes, this puts a hole right in the center of the pan of bars; but you're going to cut them into squares anyway, and just assume the one with the hole will be yours—baker's privilege!

Remove the bars from the oven, and cool to lukewarm before cutting. A plastic knife will glide right through these sticky bars without tearing them. Serve with ice cream, if desired. To serve bars warm after they've cooled, reheat briefly in the microwave, or slip them into a toaster bag and pop into the toaster. Yield: 24 bars from the 9" x 13" pan, 35 bars from the 10" x 15" pan.

Note: Using a jelly roll pan will make thinner bars (about 3/4" thick) than the 9" x 13" pan (a generous 1" thick). But you'll get more bars from the jelly roll pan, a consideration if you're baking for a potluck or bake sale.


  • star rating 10/09/2013
  • Janice from Brigham City, UT
  • I just recommended this recipe a few hours ago....I have had this recipe from King Arthur in my files for a long time...however, I noticed it said to bake for 30 minutes instead of the original 20 min the old recipe said. Foolishly, I baked them for 30 and the results were predictably, disastrous. Unfortunately, I had baked them to take to a friend for dinner....a few in the middle were tolerable. The rest went to the garbage. :( I am sticking by the old directions and baking for 20. I recommend the recipe, but advise caution at cooking longer then 20.
    Thanks for sharing your baking time and results here. We're glad you've determined which time works best for your oven and baked squares. When cookies/bars harden, you can try to soften by storing them air tight with a piece of bread or a heel of bread. Happy Baking! Irene@KAF
  • star rating 10/09/2013
  • Janice from Brigham City, UT
  • This is so fast and yummy. I have been making this for years and often get asked for the recipe. You won't be disappointed!
  • star rating 06/30/2012
  • stormrider from KAF Community
  • This recipe is a cinch to make and turns out perfectly. Best blondies I've had since I was a kid - nice chewy texture and great flavor. Will be my go-to recipe for blondies now! Thanks KAF.
  • star rating 05/27/2012
  • kaf-sub-pfilley from KAF Community
  • I made these bars following the recipe, using King Arthur white whole wheat flour, Callebaut chocolate chopped into chunks, cider vinegar, and the optional espresso powder (I used Ferrara brand). If I was to make these again, I would opt to leave the espresso powder out, since they gave the bar a bitter, almost burnt taste. Also, using an oven thermometer with the oven was exactly at 350 degrees, however my bars in a 9x13 inch metal pan were done (almost over done) at 28 minutes. They are still chewy however, but slightly dry around the edges.
    Glad to hear you kept an eye one the first bake of this one. Great feedback! Yes, different ovens and pans will effect any recipe. If you are working with a "dark" pan or one that has a dark non-stick coating, you may want to set the timer 5 minutes early, just to check. Frank @ KAF.
  • star rating 01/12/2012
  • Sarah from Duluth, MN
  • I have been making these exactly as recipe states, for several years now, for friends, family and coworkers. They always get rave reviews, and several people have asked for the recipe. Solid 5 star recipe in my book!!!
  • star rating 07/31/2009
  • Kristin from California
  • This recipe makes the most fantastic, chewy, chocolately bars around. I make these for work and family and friends and they all love them. I have had many requests for the recipe. I even sent them to a friend in Iraq and he said they were still good one week after they were baked. Recipe notes: I have made these in both a baking dish and a jelly roll pan. It takes longer to bake in the baking dish. You do need to make sure they are not overdone. They should look dry on the top and not have a depression in the middle of the pan.
  • star rating 04/29/2009
  • sarah from duluth, mn
  • I have not had any problems with this recipe, and to be honest, it is a highly requested one with my co-workers! The guys just love these with their morning coffee. It is in my recipe collection for good!
  • star rating 02/14/2009
  • Elizabeth from Rochester, NY
  • I made these based on the recipe in the KAF whole wheat baking cookbook, which is just slightly different (no chocolate chips for one thing). I was disappointed with both the taste and texture of the bars.
    Thank you for your frank comments about this recipe. The recipe for Butter-Nut Brownies from the Whole Grain Baking Book has some suggestions for making a brownie or bar without the chocolate - just butterscotch goodness! Overbaking, cooling completely and waiting 24 hours to eat the brownies so the wheat bran softens are some suggestions for getting results you may seek. Irene at KAF
  • star rating 01/29/2009
  • Annapurna from New Brunswick, Canada
  • These were okay, but to quote my mom, they were like "glorified chocolate chip cookies." When I took them out of the oven and did a taste test (gotta love getting that first taste), I noticed a patch that was still doughy. So I put them back in the oven, which was a BIG mistake. I think that that extra baking time (ten or so minutes) was part of the reason why they turned rock solid later on--though it was partly my doing, because I didn't cover them properly. Oops...