Prepare the Mayo-Ketchup Special Sauce. Combine sauce ingredients in a medium sized bowl; stir to combine. Cover and refrigerate until ready to use.
Tip: Add a pinch of sugar, dash of vinegar or lemon juice, and/or additional salt to adjust the flavor balance as desired.
Using a large heart shaped cookie cutter, form the ground beef into four heart shaped patties. Generously season both sides with salt and pepper.
On a large skillet or griddle, pan fry burger patties over medium-high heat, flipping half way through. Cook until burgers reach desired level of doneness; use a meat thermometer to check internal temperature.
During last minute of cooking, add a slice of cheese to each burger patty and cover until melted.
While burgers are cooking, prepare your veggies. Cut four even slices from the tomato, then shape each into a heart using a sharp knife. Peel the red onion, separate a few of the outer layers, cut these into four pieces, then cut each into a heart shape.
Cut the Sandwich Potato Rolls into heart shapes using a sharp knife. Cut two diagonal slices from one side of the bun, then cut a v-shape slice out of the opposite side.
Build your burgers. Spread some Special Sauce onto the cut sides of the top and bottom buns. Onto the bottom bun, layer a heart-shaped burger patty, then a heart-shaped tomato slice, a heart-shaped onion slice, and some shredded purple cabbage. Finish off with the top bun. Repeat with remaining burgers.
Serve and enjoy.