Whisk together flours, baking powder, salt and sugar in a large bowl.

Add butter and work it into the dry ingredients by hand to a coarse crumb.

Add fresh rhubarb and toss to combine.

Add vanilla extract and cream.

Mix to form a rough dough. Don't overwork it!

On a lightly floured surface pat the dough to 1" thick.

Use a cookie cutter to cut out scones.

Transfer scones to a baking sheet.

Brush scones with cream and sprinkle with turbinado sugar.

Bake at 400ºF for 25 minutes.