Splenda granular is measure for measure meaning that it would be the same amount. That wouldn't be the case if the Splenda packets are called for.
1 cup Splenda (granular)
1 Tablespoon molasses --can add an extra teaspoon if needed.
Mix together and use soon or it will clump and harden. Can still be used but is difficult.
The recipe is also on another thread along with a recipe for sweetened condensed milk made with Splenda.