In a heavy saucepan, stir the baking blend and cornstarch together. Add the milk stirring to combine. Place over medium heat and stir until the mixture begins to thicken, about 3-4 minutes. Don't let it burn.
Slowly pour half of the milk mixture into the egg stirring to prevent the egg from cooking. Pour the egg mixture back into the remaining milk mixture and stir to combine. Place back over the heat and cook until it coats the back of a spoon, about 2 minutes. Remove from the heat and stir in the yogurt and vanilla. Pour into 4 cups and top with plastic wrap so the wrap touches the custard. Refrigerate 6-24 hours. Remove and top with fresh fruit and serve immediately.
If you'd like to substitute granulated white sugar, double the quantity of Truvia used.
Recipe by Farmgirl Gourmet at https://www.farmgirlgourmet.com/2014/03/greek-yogurt-custard-fresh-berries.html