For the Fresh Berry Medley:
To make this dessert sugar free, substitute 5 packets of Truvia for the sugar in the panna cotta and 3 packets of Truvia for the sugar in the berry medley.
To make the panna cotta: Pour the milk into a small saucepan and sprinkle the gelatin evenly over the top. Whisk to combine, then set aside for 3 minutes to soften the gelatin. Whisk in the sugar.
Place the saucepan over medium heat and whisk frequently until the milk begins to steam and the gelatin dissolves completely. Do not allow the mixture to fully boil. Remove the saucepan from the heat and let cool for 15 minutes. Whisk in the buttermilk.
Pour the mixture into four 4-ounce ramekins. Cover with plastic film and refrigerate about 3 hours, until it is set.
To prepare the berries: Just before serving, put the sugar into a bowl large enough to hold the berries. Use a paring knife to slit the vanilla bean lengthwise and scrape the seeds into the sugar. Rub the seeds into the sugar with your fingertips. Add the berries and gently mix with a spoon or your hands for about 1 minute, until the berries are well coated and begin to release their juices.
Distribute the berries and their juices evenly over the tops of the panna cottas and serve.
Source: Sweet & Skinny by Marisa Chruchill