Place 1/2 c sugar and water into a medium pot and place on medium-low heat.
Stir to wet sugar. Bring to a boil, swirling pan occasionally.
Allow sugar mixture to simmer gently as you proceed with egg whites.
Place egg whites in a mixing bowl and whip until frothy on low speed using the wire-whip attachment of a standing mixer.
Add cream of tartar and turn speed to medium-high.
When soft peaks form, add 2 tbsp sugar gradually. Continue whipping until stiff, glossy peaks form.
Check the sugar/water mixture, maintain at medium-high heat until temperature reaches 120˚ C.
Drizzle the sugar into the mixer immediately. At this point the meringue should be at the stiff peak stage. Run mixer until meringue is cool.
Add room temperature butter into running mixer a couple of tablespoon at a time.
Beat until butter is combined and mixture has reached a silky consistency.
Add the Ubeness flavoring and then ube jam. Whip until thoroughly incorporated.