Prepare the caramel sauce by following the instructions here. Leave it out on the counter to cool, don't over-stir after it's begun to cool down.
Pre-heat your oven to 350*F. In a large mixing bowl, combine all of the dry ingredients including the sweetener.
In a measuring cup add your cream with 1 tsp vinegar, mix and set aside.
In another bowl, melt your coconut oil then add your 2 eggs and vanilla extract. Whisk well until combined.
Add your coconut oil mixture to your dry ingredients along with the vinegar/cream mixture. Stir well until everything is mixed and a thick batter forms.
Add 1 cup of boiling water and carefully stir until it is fully incorporated.
Grease a 19x13 inch pan with oil then pour half the batter into the pan, spreading it evenly to fully cover the bottom.
Drizzle half the caramel sauce your prepared before, then sprinkle your chocolate chips over this layer and top it with the second layer of batter.
Bake for ~40-50 min. This cake will still be very fudgey. This is okay!
Let the cake cool FULLY! For best results, leave the cake out, covered, overnight then top with the caramel sauce and pecans in the morning. You could also slice the cake into pieces and then top each piece as you serve it. Either way I promise you, if you wait overnight to eat this, it will be WAY better than the first day. You can technically eat it the first day as well but you may find the cake too gooey to slice and the flavour a bit different. The next day it's almost like super rich and fudgey brownies because the caramel layer that dissolved into the center has time to set again. Serve this hot or chilled or hot with low carb ice cream or whipped cream for an even more decadent experience.