Preheat oven to 350°F. Place all of the crust ingredients in a food processor. Pulse until mixture forms a ball. (If you don't have a food processor, use a fork or pastry blender to mash the butter into dry ingredients until crumbs form. Then use your hands to form dough into a ball.)
Press dough onto the bottom and up the sides of 6 (4-inch) ungreased, non-stick tartlet pans (with removable bottoms). Set aside.
For the filling
Whisk together egg yolks, sour cream, honey, sugar, lemon juice, zest, and salt until combined and smooth. Pour into prepared crusts. Bake until center is almost set, 25-30 minutes. Let them completely cool on wire rack. Just before serving, sprinkle with powdered sugar. Garnish with berries and edible flowers.
Notes
No food processor: If you don't have a food processor, use a fork or pastry blender to mash the butter into dry ingredients until crumbs form. Then use your hands to form dough into a ball.