Grease and flour a 9x13-inch baking dish, then preheat the oven to 350 degrees.
In a large bowl, cream sugar and butter. Add eggs and extract. In a separate bowl, combine flour, soda, and baking powder. Alternately add the flour mixture and sour cream to the butter mixture, beating until fluffy.
Prepare the filling by combining the ingredients and set it aside.
Pour half of the batter into the prepared pan, sprinkle with the filling, and add the remaining batter.
Bake at 350 degrees for 35-40 minutes or until the cake's center is done.
Meanwhile, in a saucepan, combine all the ingredients for the topping. Stir to combine.
Remove the coffee cake from the oven and pour the warm caramel topping on top.
Broil the cake, keeping an eye to prevent burning, for 2 minutes until the topping begins to bubble. Garnish with coarse sea salt.
Allow the cake to cool completely before slicing and serving. Cut it into squares and arrange on a decorative plate or platter.