Makes 1-6" cake
Make the caramel sauce:
Combine the brown sugar, water, butter, and sea salt in a saucepan over medium heat and mix well. Let mixture simmer and thicken slightly. Add the cornstarch and water slurry and combine. Take off heat and let cool completely.
For the cake:
In a medium bowl, sift together flour, cocoa powder, baking powder and salt. In another clean bowl, add the butter, instant coffee, and chocolate chips. Pour boiling water and let sit for a minute, then stir until smooth. Add the vanilla extract and sugar and mix until well combined.
Mix the flour mixture into the liquids and stir until just combined. Pour batter into a greased 6” cast iron pan or high-temperature cooking vessel of choice. Then pour cooled caramel sauce over cake batter.
Cook in your Cru oven at about 350°F for 30 minutes, rotating every 5 minutes. We put our cake pan into an 8” cast iron skillet to avoid messes from caramel overflow.