Preheat the Oven: Set your oven to 350°F (175°C). Line two mini 5 ½ x 3-inch loaf pans with parchment paper or lightly grease them to prevent sticking.

Make the Cake Batter: In a large mixing bowl, combine all of the dry cake ingredients (coconut flour, sweetener, baking powder, and salt). Whisk everything together to ensure it's well-mixed. Then add in the sour cream, eggs, and vanilla extract. Stir everything together, and finally, add the melted butter. Continue to stir until the batter is smooth.

Prepare the Cinnamon Streusel: In a separate small bowl, mix together the cinnamon, sugar-free sweetener, coconut flour, and melted butter. Use a fork or your fingers to crumble the mixture together, creating that delicious streusel texture.

Assemble the Cake: Spoon half of the cake batter into each of the mini loaf pans. Spread it evenly. Then, sprinkle half of the cinnamon streusel mixture over the batter in each pan. Top with the remaining cake batter, and finish by sprinkling the rest of the streusel on top.

Bake the Cake: Bake the cakes in the preheated oven for about 25-30 minutes. Check doneness by inserting a toothpick into the center of the cakes—it should come out with just a few moist crumbs. Allow the cakes to cool in the pans for a few minutes, then transfer them to a wire rack to cool completely.

Make the Frosting: While the cakes are cooling, make the cream cheese frosting. In a medium-sized bowl, beat the softened cream cheese and butter together until smooth. Add the powdered sweetener and vanilla extract, then continue to beat until the frosting is fluffy and well-combined.

Frost the Cakes: Once the cakes are completely cooled, spread the cream cheese frosting generously over the top of each loaf. If desired, dust with a little extra cinnamon for a finishing touch.

Slice and Serve: Cut each loaf into 6 thick slices. Now, the fun part—enjoying every bite of this decadent, low-carb, keto-friendly treat!