Heat cream, sugar, and vanilla for vanilla cream sauce in a saucepan over medium-high heat until boiling. Reduce heat and simmer, stirring frequently, until thickened, 2 to 4 minutes. Remove from the heat and pour into a small pitcher for serving. Set aside at room temperature until ready to serve.
Mix butter, cinnamon, and brown sugar for cinnamon butter together until well combined; set aside.
Stir pancake mix, milk, and eggs for pancakes together until blended. Let sit for 5 minutes.
Preheat a griddle to 350 degrees F (175 degrees C). Butter the surface, then working in batches as needed, ladle 1/2 cupfuls of batter for each pancake onto the hot griddle. Sprinkle a heaping tablespoon chopped pineapple on top of each one. Cook until the edges appear dry and the surface of the batter is no longer glossy, 2 to 4 minutes. Sprinkle a pinch or two of sugar onto each pineapple and flip. Cook until pancake is cooked through and pineapple is caramelized, another 2 to 4 minutes. Place pancakes on a plate in a warm oven and repeat the process to cook remaining pancakes.
Serve pancakes with a dollop of cinnamon butter and drizzle vanilla cream sauce over top.