Grate 113 g butter; freeze. Cube remaining
Process 100 g flour + sugar + salt. Add cubed butter; blend to paste
Break into chunks. Add remaining flour; pulse
Add grated butter; toss
Mix egg + ice water; sprinkle over
Bring dough together; chill 2 hours
Roll into rectangle; fold (book fold) 6 times
Roll to 15×18 inches; cut 6-inch × ¾-inch strips
Wrap strips around clothespin molds
Bake at 375°F for 9 minutes
Cool completely; remove molds
Cook sugar, flour, milk, cream until thick
Cool to 80°F
Beat mixture; add butter slowly
Add vanilla + salt; whip until fluffy
Fill pastry shells using piping bag
Store or serve