In a medium saucepan, combine the brown sugar, distilled water, and unsalted butter. Place the saucepan over medium-high heat.
Bring the mixture to a boil, ensuring constant stirring to prevent any ingredients from sticking to the base of the saucepan.
Upon reaching a boil, introduce the light corn syrup to the mixture. Adjust the heat to low, allowing the solution to simmer for a duration of 1-2 minutes. Subsequently, remove the saucepan from the heat source.
Gradually incorporate the smooth peanut butter and marshmallow creme into the mixture, ensuring a consistent blend.
Once well mixed, infuse the mixture with pure vanilla extract. If desired, the maple extract can also be added at this juncture. Stir until the extracts are thoroughly incorporated.
Allow the mixture to cool to room temperature. Once cooled, it should be transferred to a sealed container suitable for refrigeration.
For optimal taste, serve the spread atop biscuits, English muffins, or toast. Ensure to store the unused portion in a refrigerator.