Preheat the oven to 180C/350F. Grease two 8-inch cake pans and set aside.
In a large mixing bowl, add your dry ingredients and mix well. Next, add in the vinegar, vanilla extract, oil, and water, and mix until fully combined.
Distribute the cake batter evenly between the two cake pans. Bake for 25-30 minutes, or until a skewer comes out clean.
Remove from the oven and let the cakes cool completely, before slicing in half and frosting.
To make the peanut butter nougat frosting
In a large bowl, beat together your butter and peanut butter until smooth. Slowly fold in your powdered sugar and vanilla until smooth and creamy.
To layer the cake
Place one single bottom layer of one of the cakes on a flat surface or serving dish. Lightly spread a thin layer of caramel, followed by 1/4 of the peanut butter frosting. Top with extra caramel. Place the top layer of the cake. Repeat the process, until you have all 4 layers on top of one another. Carefully add extra frosting on top, if desired.
* You can use white sugar, brown sugar, or sugar free subs, like erythritol and monk fruit sweetener.TO STORE: The cake should always be stored in the refrigerator, covered. The cake will keep fresh for up to 2 weeks. Let the cake sit for 30 minutes before serving. TO FREEZE: Place the cake in a freezer friendly container and store in the freezer for up to 6 months. Thaw the cake in the refrigerator overnight.