Making Delightful Cinnamon Roll Bliss Bars can be a fun and rewarding experience. Follow these steps to create your delicious treat:

1. Preheat the Oven: Preheat your oven to 350°F (175°C) and grease a 9×13-inch baking dish.

2. Mix Dry Ingredients: In a large bowl, whisk together the flour, sugar, baking powder, baking soda, and salt to combine.

3. Cream Butter and Sugar: In a separate bowl, cream together the softened butter and granulated sugar until light and fluffy. This should take about 2-3 minutes.

4. Add Eggs and Sour Cream: Beat in the eggs, sour cream, and vanilla extract until fully combined.

5. Combine Mixtures: Gradually add the dry ingredients to the wet ingredients, stirring until just combined. Do not over-mix.

6. Prepare Cinnamon Mixture: In a small bowl, combine brown sugar and ground cinnamon, mixing well to create your cinnamon filling.

7. Layer the Batter: Spread half of the batter evenly into the prepared baking dish. Sprinkle the cinnamon-sugar mixture evenly over the batter, then dollop the remaining batter on top and spread gently.

8. Bake: Place the dish in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.

9. Cool Down: Let the bars cool in the pan for about 20-30 minutes. They will firm up as they cool.

10. Make Icing: In a small bowl, whisk together powdered sugar, milk, and vanilla extract until smooth. Adjust consistency with more milk if necessary.

11. Drizzle Icing: Once the bars are mostly cool, drizzle the icing over the top, allowing it to set for a few minutes.

12. Slice and Serve: Cut into even squares and get ready to enjoy this delightful treat!