To make the Crostini:

1. Preheat oven to broil.
2. Using a 3-inch heart-shaped cookie cutter, cut one heart from each slice of bread.
3. Place on cookie sheet and brown under broiler until golden, turning halfway for even browning.
4. Remove from oven, flip each heart-shaped crostini over and brown the other side (this just takes a few minutes; don’t leave unattended or they may burn!).
5. Remove from oven and transfer to a cookie cooling rack and cool completely or overnight.

To Make the Macerated Strawberries:

1. Place chopped strawberries into a small non-reactive (glass or plastic) bowl.
2. Add vinegar and sugar and stir to combine.
3. Refrigerate at least an hour or overnight.

To Assemble Sweetheart Strawberry Crostini:

1. Using a dinner knife or a butter knife, carefully spread Mascarpone cheese onto each heart-shaped crostini toast.
2. Remove strawberries from the refrigerator, add basil strips and stir to combine.
3. Spoon macerated strawberries and basil on top of Mascarpone, dividing evenly.
4. Zest lemon over top.
5. Serve immediately.