Begin by boiling a large pot of salted water. Add the cubed potatoes and cook until tender, about 15-20 minutes. Drain and return to the pot.
In the pot with the drained potatoes, add 2 tablespoons of butter, milk, sour cream, garlic powder, salt, and pepper. Mash until smooth and creamy. Set aside and keep warm.
In a large skillet, melt the remaining 2 tablespoons of butter over medium heat. Add the minced garlic and sauté for about 1 minute until fragrant.
Add the shrimp to the skillet and season with paprika, salt, and pepper. Cook for 2-3 minutes on each side until the shrimp are pink and opaque.
Pour in the heavy cream and stir to combine. Let the mixture simmer for 2-3 minutes until slightly thickened. Stir in the chopped parsley.
Serve the creamy garlic shrimp over a generous scoop of mashed potatoes. Garnish with additional parsley if desired.