Preheat your oven to 350°F (175°C). Grease and line a 9x13-inch baking pan with parchment paper, allowing the paper to overhang for easy removal.
In a medium bowl, whisk together flour, baking powder, and salt. Set aside.
In a large mixing bowl, cream together 3/4 cup butter and granulated sugar until light and fluffy, about 2 minutes.
Add eggs one at a time, mixing well after each addition. Stir in vanilla extract.
Gradually mix in the dry ingredients and buttermilk, alternating between the two, starting and ending with the dry ingredients. Mix until just combined.
Pour the batter into the prepared pan and smooth the top with a spatula. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool completely in the pan on a wire rack.
To make the frosting, beat 1 cup butter in a bowl until creamy. Gradually add powdered sugar and heavy cream, beating until smooth.
Add pink food coloring to the frosting until the desired color is reached.
Spread the frosting evenly over the cooled cake and top with sprinkles.
Chill the frosted cake for about 30 minutes before slicing to allow the frosting to set for clean cuts.