Adjust oven rack to lower-middle position. Heat oven to 400 degrees F (205 degrees C). Prepare a half sheet pan by greasing it all over with some butter.
Mix All-Purpose Flour (4 cup), Fine Salt (1 teaspoon), Baking Powder (2 tablespoon), and Granulated Sugar (1/3 cup) in medium bowl.
Using the large holes of a box grater, grate Unsalted Butter (1 cup) into the dry ingredients.
Toss butter with flour to coat. Use a pastry cutter or a fork to finish cutting butter into the flour. Or scoop up coated butter with both hands, then quickly rub the butter into dry ingredients with fingertips until most of the butter pieces are the size of split peas.
In a medium bowl, mix Egg (2), Greek Yogurt (1/2 cup), and Milk (1/2 cup), then pour into the flour mixture. Toss with a fork until large clumps form.
Transfer the dough to the prepared pan and press into an even layer. You can lightly moisten your hands if necessary. The pressed dough should be about 3/4-inch thick.
Brush dough with Heavy Cream (2 tablespoon) and sprinkle with Raw Sugar (2 tablespoon).
Bake until golden brown, about 15 minutes. Place baking sheet on wire rack and cool shortcake until room temperature.
Preheat the oven to 350 degrees F (175 degrees C). Line a half sheet pan with parchment paper, making sure the paper goes up the edges of the pan.
Chill a non-reactive, deep bowl and beaters mixer in freezer for at least 20 minutes.
Place Plum (750 gram) in a bowl. Toss with Honey (1/2 cup), zest and juice of the Lemon (1) and Vanilla Extract (2 teaspoon).
Pour plums onto the prepared sheet pan and place Cinnamon Stick (3) and Whole Cardamom Pods (5) here and there about the plums.
Roast the plums for 20 to 25 minutes, turning once, until just softened. Let the plums cool in their syrup, then discard the cinnamon sticks and cardamom. Reserve until serving.
Add Heavy Cream (3 cup) to the chilled bowl. Sift in Powdered Confectioners Sugar (1 cup) and beat on low speed until small bubbles form, about 30 seconds. Increase speed to medium and continue beating until beaters leave a trail, about 30 seconds more. Increase speed to high and continue beating until cream is smooth, thick, and nearly doubled in volume, about 20 seconds for soft peaks.
Add in the Greek Yogurt (3/4 cup) and whip for another ten seconds or so, until whipped cream is thick. If necessary, finish beating by hand to adjust consistency. Keep chilled until ready to serve.
To serve, spoon the chilled Greek yogurt whipped cream evenly on top of the cooled shortcake. Use your spoon to create swoops in the cream.
Carefully disperse the roasted plums on top of the cream and finish by drizzling the roasted plum juice over the plums.
Slice and serve. This shortcake is best eaten within the first 2 hours. Any leftovers should be covered and stored in the refrigerator.