Line a baking sheet with parchment paper and set aside. In a large skillet, cook the chopped bacon over medium heat until very crispy. Remove bacon pieces with a slotted spoon to a paper towel-lined plate to drain. Reserve about 1 tablespoon of bacon fat in the skillet. (You can discard the rest or save for other uses.)

In the same skillet (with 1 tbsp bacon fat), add the granulated sugar and water. Stir until sugar dissolves over medium-high heat, then bring to a boil. Boil without stirring until the mixture turns an amber caramel color (about 5-7 minutes). Remove from heat.

Quickly stir in the baking soda and the cooked, crumbled bacon pieces. The mixture will foam. Immediately pour and spread the brittle onto the prepared parchment-lined baking sheet in a thin layer. Let it cool completely and harden (about 30 minutes). Once cool, break into small pieces. You can roughly chop it further or pulse briefly in a food processor.

Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans, then line the bottoms with parchment paper.

In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.

In a large mixing bowl, cream together the softened butter, granulated sugar, and brown sugar with an electric mixer until light and fluffy (about 3-5 minutes). Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract.

Gradually add the dry ingredient mixture to the wet ingredients in three additions, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined after each addition; do not overmix. Fold in the mashed bananas.

Divide the batter evenly between the two prepared cake pans. Bake for 30-35 minutes, or until a wooden skewer inserted into the center comes out clean. Let the cakes cool in the pans for 10-15 minutes before inverting them onto a wire rack to cool completely.

In a large mixing bowl with an electric mixer, beat the softened cream cheese and butter until smooth and creamy (about 2-3 minutes).

Add the creamy peanut butter and beat until fully incorporated.

Gradually add the sifted powdered sugar, 1 cup at a time, beating on low speed until combined, then increasing to medium speed. Add the milk or cream (starting with 2 tablespoons) and vanilla extract. Beat until smooth and fluffy, adding more milk if needed to reach your desired consistency. Stir in a pinch of salt to balance the sweetness.

Once the cake layers are completely cool, use a serrated knife to level the tops if desired.

Place one cake layer on your serving plate. Spread about 1 cup of peanut butter frosting evenly over the top. Sprinkle about half of the crushed bacon brittle over the frosting.

Carefully place the second cake layer on top. Cover the entire cake with the remaining peanut butter frosting, spreading it evenly over the top and sides.

Garnish the top and sides of the cake with the remaining crushed bacon brittle. Slice and serve. Enjoy your "The King" Cake!