-
1
Position rack in center of oven and preheat to 425F.
-
2
Whisk buttermilk, egg and vanilla extract in medium bowl to blend; transfer 1 tablespoon mixture to small bowl and reserve for glaze.
-
3
Sift flour, sugar, baking powder and salt into large bowl; add butter.
-
4
Using electric mixer, beat until mixture resembles coarse meal, about 3 minutes.
-
5
Add buttermilk mixture and blend just until soft moist dough forms.
-
6
Turn dough out onto lightly floured surface.
-
7
Using floured hands, gather dough into ball and knead gently for 6 turns.
-
8
Transfer dough to ungreased baking sheet.
-
9
Shape dough into 8-inch round.
-
10
Brush top with reserved 1 tablespoon buttermilk mixture.
-
11
Bake cake until top is golden brown and tester inserted into center comes out clean, about 20 minutes.
-
12
Transfer cake to rack and cool completely.
-
13
Toss plums, peaches, raspberries and 1/3 cup sugar in large bowl to blend.
-
14
Let stand 30 minutes.
-
15
Meanwhile, beat mascarpone, whipping cream, 1/4 cup powdered sugar and vanilla in large bowl until firm peaks form.
-
16
Refrigerate until ready to use.
-
17
Cut off top 1/3 of cake.
-
18
Using small knife and leaving 1/2-inch border at edge, cut out enough of cake bottom to form 1/2-inch-deep indentation.
-
19
Spread half of mascarpone cream in indentation.
-
20
Using slotted spoon, remove fruit from bowl; mound onto cream.
-
21
Reserve fruit juices in bowl.
-
22
Spread remaining mascarpone cream over fruit.
-
23
Cover with top of cake.
-
24
Refrigerate cake and reserved juices separately, at least 3 hours and up to 6 hours.
-
25
Let cake stand at room temperature 30 minutes before serving.
-
26
Dust with powdered sugar.
-
27
Cut into wedges.
-
28
Drizzle with reserved fruit juices and serve.
