Preheat the oven to 350 degrees F and grease a 9x13 cake pan, set aside.
Mix together all ingredients until fully combined and transfer to the prepared cake pan. The batter will be thick and you will need to use a rubber spatula to spread it out.
Bake for 28-32 minutes or until a cake tester inserted into the center comes out clean.
Let cool for 30 minutes and stab with a fork all over the top of the cake.
Filling
Whisk together the sweetened condensed milk and chocolate syrup until fully incorporated.
Once fully mixed, pour over the top of the holes in the cake.
Frosting
In a large bowl or stand mixer fitted with a whisk attachment, beat together the frosting ingredients until thick and fluffy.
Spread the whipped cream over the top of the cake and top with chocolate sauce, sprinkles, or fruit, if desired.