Starbucks Key Lime Crumb Cake

 On a recent vacation we passed through the Miami airport where I came upon something I'd never seen at Starbucks before-Key Lime Crumb Cake.  Do you have this at your Starbucks or is this a Florida thing?  If you're not sure, look for a rainbow in the sky or angels hovering over the building.  That would be a sign.

Never tasting this, I foolishly bought only one piece to share between four of us.  After one bite I wanted to invoke the "hands off twerps, 36 hours of labor and 2 c-sections--you owe me!" clause.  But I didn't, cuz I'm a giver.  Although, between you and me, I took giant bites when it was my turn.  I have been obsessed with recreating this ever since.

It's a basic lemon crumb cake with a layer of key lime curd through it.  I ended up with more curd in mine than the Starbucks version.  You can decide how much you like.  You can buy the curd if need be but c'mon, man up and make it yourself.  Key limes are hard to find and not available all year long so bottled key lime juice is the way to go.  This is a great dessert or breakfast/brunch item.  Make it for Mother's Day! And in the spirit of the day, share some with your twerps.

Starbucks Copycat Key Lime Crumb Cake
Serves 10-12

KEY LIME CURD:

4 extra-large eggs
1/2 c sugar
3 t finely grated lime zest
1/2 c key lime juice
4 T sweetened condensed milk
a pinch of salt

1.  Set a fine-mesh sieve over a bowl. 

2.  In a small saucepan, cook the eggs, sugar, lime zest and juice over moderate heat, whisking constantly, until thickened, about 3-5 minutes. 

3.  Strain the lime curd into the bowl and whisk in the condensed milk. Cover with plastic wrap and refrigerate for at least 1 hour, until chilled.

 Lemon zest mixed w/sugar

CRUMB CAKE:

6 T unsalted butter, at room temperature

3/4 c granulated sugar

2 extra-large eggs, at room temperature

1 t vanilla extract

1 t grated lemon zest

2/3 c sour cream

1 1/4 c all-purpose flour

1 t baking powder

1/4 t baking soda

1/2 t kosher salt

1.  Preheat the oven to 350.  Use baking spray (or butter and flour) to coat a 9-inch cake pan.  Line with a parchment round.
2.  Add your lemon zest to the granulated sugar and using your hands rub the zest into the sugar until it's fully incorporated into the sugar.
3.  Cream the butter and lemon sugar in the bowl of an electric mixer fitted with the paddle attachment on high speed for 4 to 5 minutes, until light. Reduce the speed to low and add the eggs 1 at a time, then add the vanilla and sour cream.
4.  In a separate bowl, sift together the flour, baking powder, baking soda, and salt. With the mixer on low speed, add the flour mixture to the batter until just combined.

STREUSEL TOPPING:

1/4 c granulated sugar
1/3 c light brown sugar, lightly packed
8T (1 stick) unsalted butter, melted

1 1/3 c all-purpose flour

pinch of kosher salt

1.  Combine the sugars in a bowl. Using a fork, stir in the melted butter, salt and then the flour. Mix well until little clumps form and set aside.

 Lime curd layer on top of batter (excuse the crappy lighting)

ASSEMBLING THE CAKE:

1.  Put 1/3 of your cake batter into the greased and parchment coated pan.  Smooth with an offset spatula. 
2. Add 2/3 of your lime curd to the pan.  You'll have a little curd leftover for snacking!  Smooth the curd into a circle over the batter but leave a 1/2 inch border on all sides without curd.  You want the curd to stay inside the cake, not seep out to the edges.
3. Spoon dollops of the remaining cake batter over the curd layer and carefully smooth out to edges of pan.  Take care to leave the curd layer intact.
4.  Sprinkle streusel layer on top.
5. Bake for 40-50 minutes.  When testing for doneness, poke a skewer only into the batter layer.  If you go down to the curd, you will think your batter is not cooked yet.
6.  Let cake cool for 15-20 minutes.  Run a sharp knife around the edges of your cake pan to release sides.  Turn cake out onto platter and cool completely.
7.  MOST IMPORTANT:  Refrigerate for at least 2 hours before serving.  The curd needs to chill and solidify again before cutting into the cake.  Sprinkle with confectioners sugar before serving.

8. Cake must be stored in refrigerator.