Blueberry Compote: Place all but ½ cup blueberries, sugar, starch and lemon juice into a saucepan and lightly simmer over medium-low heat for about 15 minutes, stirring and lightly crushing blueberries as the mixture cooks down.
Strain blueberry mixture and return strained liquid back to saucepan with remaining blueberries. Gently simmer for 5 to 7 minutes, stirring occasionally. Set aside and allow compote to cool.
Sprinkle gelatin over 2 tablespoons water and bloom.
Combine remaining water, honey, sugar, and salt into a saucepan and bring to a boil. Continue to boil until mixture reaches about 288˚F.
Beat yolks together in a stand mixer (with a whisk attachment), until light and fluffy. With the motor running, slowly drizzle hot honey mixture into the yolk mixture and beat together until completely combined. Add gelatin mixture to the used saucepan to melt the gelatin. Pour mixture into the stand mixer along with the vanilla paste/extract and beat together.
Fold in ⅓ of the whipped cream until fully incorporated. Fold in the remaining whipped cream until light and fluffy.
In a quart container add ⅓ of semifreddo mixture. Dot with 1/3 of the blueberry compote and swirl compote into semifreddo. Repeat in layers until all semifreddo and blueberry compote has been used.
Cover with plastic wrap and place in freezer for at least 6 hours. Serve once frozen.