Preheat the oven to 350 degrees. Line a baking sheet with parchment paper.
In a large bowl, sift together the flour, baking powder and salt (a wire whisk is great for this). Using a pastry cutter or two knives, cut the ¼ cup of cold butter into the flour mixture until it looks like coarse crumbs. Stir in the diced plums.
In a small bowl, whisk together the eggs, milk, honey and vanilla extract until well-blended. Make a well in the center of the dry ingredients and pour in the egg mixture. Fold the dry ingredients into the egg mixture until just moistened. Stir gently from the inside out until well-combined.
Using a large cookie scoop (or 2 tablespoons), drop 12 scone rounds onto the prepared baking sheet. Sprinkle liberally with coarse sugar.
Bake for 18-20 minutes, until cooked through. The scones are done when the tops have bits of golden brown.
Recipe by Sarah's Cucina Bella at http://sarahscucinabella.com/2015/01/30/mini-honey-plum-scones/