Stir together almond flour, brown sugar, and salt in a bowl.

Pour melted butter and vanilla extract into the flour mixture and stir to completely saturate the dry ingredients until it becomes the consistency of wet sand.

Press the mixture firmly into an 8x8" pan lined with parchment paper.

Chill in the fridge while you prepare the caramel.

In a small pot on medium heat, bring the brown sugar, butter, and condensed milk to a boil while stirring constantly. 

Keep it at a boil for 2-3 minutes while the caramel thickens. When the caramel parts on both sides when you drag a spatula through it and joins back together after 1-2 seconds, it's ready.

While the caramel is still warm, pour it over the shortbread layer and use an offset spatula to smooth it into an even layer. Let it chill in the fridge while you prepare the chocolate ganache.

Set aside your chopped dark chocolate and white chocolate in two separate bowls. Heat the heavy cream on medium heat until bubbles just begin to form.

Pour 100g of the hot cream over the dark chocolate and the remaining 25g over the white chocolate. Let sit undisturbed for 1-2 minutes before stirring both chocolate ganaches until they're melty and smooth.

Pour the dark chocolate ganache over the caramel layer and smooth into an even layer with an offset spatula.

Use a spoon to place small blobs of white chocolate ganache on top of the dark chocolate layer. Gently run a chopstick or knife through the ganache layer only in a zigzag pattern going left and right and then in an up and down motion without lifting up to create a marbled pattern.

Let this chill in the fridge again for at least 1 hour until all the layers have set.

Remove the shortbread from the pan by lifting it up by the parchment paper overhangs. Run a sharp knife under hot water between each slice and cut into bars.