Not your ordinary layered bar, carmelitas sandwich a sticky caramel, chocolate, and pecan filling between two layers of buttery, streusel-like shortbread studded with oats. Their variety of both flavors and textures make them an irresistible temptation and an easy crowd-pleaser.
Preheat the oven to 350°F. Lightly grease a 9" x 13" pan and line with a parchment sling.
To make the crust: In a large bowl or the bowl of a stand mixer fitted with the flat beater attachment, combine the flour, oats, sugar, baking soda, and salt. Add the butter and stir with a rubber spatula or on low speed of a stand mixer until the mixture is crumbly; stop before the mixture comes together into a cohesive dough.
Transfer two-thirds of the crumb mixture (about 3 cups or 540g) to the prepared pan and press it evenly into the edges and corners, using the bottom of a measuring cup to pack it into a smooth layer.
Bake the crust for 10 to 15 minutes, until it's puffed slightly and is golden-brown all over.
Remove the crust from the oven and set it aside to cool for 10 minutes.
To make the filling: In a medium saucepan, combine the golden syrup, sweetened condensed milk, brown sugar, butter, vanilla, and salt. Set over medium heat and cook for 7 to 10 minutes, stirring freqently at the beginning and constantly towards the end, until the mixture becomes thick and pale and is bubbling vigorously around the edges of the pot and slowly burbling at the center.
Pour the caramel onto the crust, spreading it to the edges, and allow to set, about 15 minutes.
Scatter the chocolate chips and pecans evenly over the firm caramel layer, then scatter the remaining crumb mixture over top, breaking it up until smaller pieces as necessary.
Bake the bars for 20 to 25 minutes, until the crust is lightly browned and the caramel is bubbling around the edges.
Remove the bars from the oven, loosen the edges, and allow them to cool completely in the pan before cutting and serving.
Store wrapped bars at room temperature for a few days; freeze for longer storage.
You can skip the homemade caramel layer and use our Caramel Baking Block instead. Cut the 16-ounce block into 1/2" pieces, then place it in a small saucepan or microwave-safe bowl with 2 tablespoons (28g) milk. Melt over low heat or in short burts until smooth. Use as directed in step 7.
