Line cookie sheet with parchment paper or wax paper.
Place cinnamon hearts in a sandwich baggie and use hammer to crush into small pieces. Reserve a handful of whole hearts.
Carefully melt chocolate in microwave. Heat in bursts of 20 seconds on medium-high, checking and stirring between. Once chocolate is mostly melted, stir until all remaining chocolate is melted and smooth.
Pour melted white chocolate (reserving quarter cup of chocolate) into lined pan and spread evenly with a soft spatula to about 1/4" thickness .
Immediately colour the reserved chocolate to the desired shade of pink.
Drizzle pink chocolate over still liquid white chocolate and gently drag a chopstick through to marble the colours together.
Sprinkle crushed cinnamon hearts and place a few whole hearts on top.