Heat grill to medium-low (350° to 400°; if you'll be using a nonstick muffin pan, don't let grill go over 450°). Stir together crème fraîche and honey in a bowl. Chill.
Whirl eggs, flour, milk, and salt in a food processor until smooth. Pour batter into a glass measuring cup.
Combine sugar (use 1/2 cup if fruit is very sweet, 3/4 cup if it's more tart) and lavender in a large cast-iron or other ovenproof frying pan and pat out evenly. Arrange apricots in sugar, cut side down.
Set a muffin pan on one side of cooking grate and set pan with fruit on other side; cook, grill lid down, 5 minutes. Put a piece of butter in each of 6 muffin cups, close lid, and cook until it starts to brown, 30 to 60 seconds. Pour batter into cups with butter, filling about halfway. Grill, lid down, until puffs are golden and syrup around apricots forms big, shiny bubbles and is deep golden brown, 10 to 15 minutes.
Loosen puffs from pan with a small metal spatula and set on plates; they'll sink a bit and form a depression. Turn fruit over in syrup, using a wide metal spoon. Fill puffs with some crème fraîche and an apricot and syrup. Spoon remaining apricots and syrup next to puffs, and serve warm with more crème fraîche and a lavender sprig if you like.