Preheat oven to 350°F. Grease a standard sized donut pan and set aside.
In a medium bowl, combine flour, brown sugar, baking powder, and salt. In a separate bowl, combine egg, milk, vegetable oil, yogurt, vanilla extract, and lemon. Carefully pour the wet ingredients into the dry, mixing until just combined. Mixture will be thick.
Spoon batter into a large ziplock bag and cut a ½ inch hole in one corner, creating a makeshift piping bag. Pipe the dough into the donut molds, filling ¾ of the way to the top of the molds. Bake for 12 minutes.
Allow donuts to cool before frosting.
To make the lavender white chocolate, create a double boiler using a small bowl and small saucepan. Heat the white chocolate and lavender buds until melted. Dip each donut into the chocolate, then sprinkle with more dried lavender. Once chocolate hardens, serve!