Blackberry-Lime Dessert Bars

Remember those Brown Butter Peach Bars that were all the rage in the food blogosphere a couple summers ago?  Well, the thing is, once you make them, you keep thinking about them and you're bound to do something with the recipe again.

For those of you who may have missed it, I'll catch you up: it's a recipe from Big Sur Bakery that was featured in the New York Times Dining Section. It's a two-day process, and the steps include making peach jam and browning two separate batches of butter.  One batch is frozen and then cut into flour and powdered sugar for the crust, the other is used for the filling.  The end result is buttery, ooey-gooey, citrusy-peach deliciousness on a sandy-delicious shortbread crust.  They truly are some sort of amazing. 

It's been a year since my first attempt with Brown Butter Peach bars.  Last week I found myself with a little more than a pint of freshly made blackberry jam and a hankering for some buttery-sweet pastry.  What else was I to do?

Take a perfectly good recipe, and make it better. Oh, yes, I did.

You may remember that my only beef with the original bars was that the orange in the jam and filling overpowered the peach a little bit.  So not only did I substitute blackberry for the peach, I substituted lime for the orange and dialed back the citrus quite a bit.  Also, I didn't bother with browning the butter for the crust (gasp).  Yes, I know, the whole point of a "Brown Butter Peach Bar" is the brown butter and the peaches (well, no, if it were the peaches, they wouldn't have put so much citrus in them); hence, the name change, "Blackberry Lime Dessert Bars."  The crust browns in the oven, and in the summer heat when I'm in the mood to bake, I am in the mood to bake right then, not to brown some butter and freeze it overnight and see if I'm still motivated the next day.  So I skipped browning the butter. And I skipped the vanilla bean too.  I just didn't feel like another flavor element was necessary (and I didn't feel like finding the right knife to scrape the seeds out of a vanilla bean).  I admit it, I've completely bastardized their recipe, but you know what, I think these Blackberry Lime Dessert Bars are every bit as amazing as the Brown Butter Peach Bars. And since this streamlined version takes a little less time, well... You might as well try it and let me know what you think.

While the peach version seems at home as an indulgent breakfast pastry, this version strikes me more as dessert.  I served it to dinner guests in small squares topped with vanilla ice cream.  The vanilla ice cream pairs with the tangy lime, the summery blackberries and the buttery crust to make you want to sit out on the patio for just a little while longer. Of course, we had leftovers, and those we ate as snacks... and a couple of them were "pre-breakfast snacks."

Notes:
Yes, I made my own jam, but you could certainly use a good purchased jam.  (And for that matter, you don't even have to do blackberry, but I really like the blackberry-lime combination.)  In fact, this recipe would be a great place to showcase a really good jam.

And finally, yes, I am leaving you with a naked lime, but I'm sure you can figure out something to do with the juice.

Blackberry-Lime Dessert Bars
Adapted from the Big Sur Bakery via The New York Times
A buttery, melt-in-your-mouth, perfectly-sandy shortbread crust, topped with a sweet-tangy, summery blackberry-lime, just-barely-crusty, bright-citrus-kissed... You get the point.
Makes about 30-36 bars (one 13x9" pan).

For the Crust

1 cup (2 sticks) unsalted butter, cut into small cubes
1/2 cup confectioner (powdered) sugar
1 cup whole wheat pastry flour
1/2 cup all-purpose flour

For the filling/topping

10 tablespoons unsalted butter
1 pint (2 cups) seedless blackberry jam*
zest of 2 limes, plus the juice of 1 lime
3 teaspoons vanilla extract, divided
3 eggs
1 cup sugar
1/2 cup all-purpose flour

1.  Make the crust:  In a medium bowl, stir together confectioner sugar and flours.  Cut in 1 cup butter using a pastry blender, two knives in a criss-cross motion, or your fingers.  When butter is evenly distributed, press crust into an ungreased 13x9" glass baking dish.  The crust does not need to go up the sides, just evenly cover the bottom of the pan and press it firmly.  Refrigerate crust 30 minutes.  Then bake at 375º for 18 to 20 minutes.  Crust should be golden.  Let crust cool at least 30 minutes before filling.

2.  Melt 10 tablespoons butter in small saucepan over medium heat.  Watch butter carefully as it browns.  Remove from heat when it smells nutty and is nicely browned, before it burns.  Let cool.

3.  Put jam into a small mixing bowl (and bring to room temperature if refrigerated).  Stir in juice of 1 lime and 2 teaspoons vanilla extract.  Set aside.

4. In medium bowl, whisk together 3 eggs, the zest of 2 limes, 1 cup sugar and 1/2 cup all purpose flour.  Whisk in cooled browned butter to make a thin batter.

5.  Assemble:  Spread half of the batter over the cooled crust.  Tilt pan to spread evenly.  Distribute jam fairly evenly over the batter.  It doesn't have to perfect.  Little pockets of jam in the finished bars are what you want. (Use a pastry bag with a 1/4" tip if you have one, or put your jam into a Sandwich- or Quart-size zip-lock bag.  Squeeze out as much air as possible and seal the bag.  Snip off one the bottom corners of the bag to make a small opening.  Then squeeze ribbons of jam evenly onto the batter.  Alternatively, dollop small spoonfuls of jam over the batter.)  Finally, pour the remaining batter over the jam.  Tilt pan to distribute evenly.  Bake at 375º for 25 to 30 minutes, until golden brown. Cool completely in pan before cutting into bars.

*I made blackberry jam using the recipe inside the box of Sure-Jell Pectin for Less or No Sugar Needed Recipes. All you need is the pectin, blackberries and sugar.  When you skip the canning step, which you can do if you will be storing your jam in the fridge and using within a month or so, it's a quick process.