In a heavy-bottomed saucepan, combine the heavy cream, white sugar, brown sugar, and pure maple syrup.
Bring the mixture to a boil over medium heat, stirring occasionally.
Cook until a candy thermometer reads exactly 238°F (softball stage).
Remove from heat immediately and transfer the hot mixture to a large Pyrex pitcher.
Leave the thermometer in the pitcher and let the mixture cool undisturbed to 110°F.
Once cooled, use an electric hand mixer to stir the mixture until it turns opaque.
Pour the fudge into a silicone muffin pan, filling each cup 2/3 full.
Let the fudge set slightly, then use a smooth knife to score a "+" into the top of each cup.
Allow to set completely, then turn out the molds and cut along the lines to create 4 pieces per cup (48 pieces total).