Shortcake Biscuits : 
2½ cups all-purpose flour
1 tablespoon baking powder
½ teaspoon baking soda
½ teaspoon salt
⅓ cup +1 tablespoon sugar
½ cup (1 stick) cold butter or margarine,
cut into pieces
1 large egg, separated
1 cup buttermilk
Sugared Strawberries :
2½ pounds strawberries (8 cups)
2 tablespoons sugar
Whipped Cream :
1 cup heavy or whipping cream
2 tablespoons sugar
1 teaspoon vanilla extract

Step1
Preheat oven to 425°F. 
Prepare shortcakes :
In large bowl, combine flour, baking powder, baking soda, salt, and ⅓ cup sugar. Cut in butter.

Step 2
In small bowl, with fork, beat egg yolk with buttermilk  stir into flour mixture just until mixture forms soft dough that leaves side of bowl. 

Step 3
On floured surface,with floured hands, knead dough 6 to 8 times to combine; pat dough to ¾-inch thickness.

Step 4
Cut out shortcakes :
place 1 inch apart on ungreased large cookie sheet.Press trimmings together cut to make 8 biscuits in all. 

Step 7
Prepare whipped cream :
In medium bowl, with mixer at medium speed, beat cream, sugar, and vanilla until stiff peaks form.

Step 8
Split each shortcake horizontally. Place bottom halves on 8 dessert plates. Layer berries and cream over shortcake bottoms; replace tops. Dollop with cream  and berries.