The picture in the martha stewart magazine totally sold me on this recipe. I was really happy that mine turned out almost as cool as hers. :) If the plums were sweeter, I think this would have been a 5 star dessert. I will try this again in the summer when the plums will be juicier.
2 1/2 cups plus 2 tablespoons all-purpose flour (spooned and leveled), plus more for rolling
1 cup (2 sticks) cold unsalted butter, cut into pieces
5 tablespoons plus 1 teaspoon sugar
1 teaspoon salt
1/2 cup ice water
1/4 cup whole, skin-on almonds, toasted
5 to 6 plums, halved, pitted, and sliced inch thick (keep slices together)
1 to 2 tablespoons heavy cream (I didn't have heavy cream so I used an egg wash)
In a food processor, combine 2 1/2 cups flour, butter, 1 teaspoon sugar, and salt; pulse until mixture resembles coarse meal. Sprinkle with 1/4 cup ice water. Pulse until dough is crumbly but holds together when squeezed (if necessary, add up to 1/4 cup remaining ice water, 1 tablespoon at a time). Dont overmix. Remove dough from processor and shape into a disk; wrap in plastic and refrigerate 1 hour. Meanwhile, wipe bowl of food processor clean and add almonds, 3 tablespoons sugar, and 2 tablespoons flour; pulse until ground to a coarse meal.
Preheat oven to 350 degrees. On a floured surface, roll out dough to 1/4-inch thickness. Transfer to a parchment-lined baking sheet; sprinkle almond mixture over dough. With a spatula, transfer plums to dough; press lightly to fan out, leaving a 2-inch border. Fold edge of dough over fruit. Refrigerate 20 minutes. Brush crust with cream; sprinkle galette with 2 tablespoons sugar. Bake until crust is golden and underside is cooked through, about 70 minutes.