Milk Skin Crisp Pastry

This is a beloved traditional Northern Chinese (especially Tianjin/Beijing-style) shortbread-like pastry famous for its ultra-crisp, melt-in-your-mouth texture —  (crumbly to the point of falling apart).

 It features a buttery, nutty base cookie layered or topped with a creamy, meringue-like  (milk skin) made from whipped egg whites and powdered sugar, giving a rich milk aroma and airy contrast. 

The result is addictive, not overly sweet, and perfect as a tea snack or festival treat.

This home version is beginner-friendly, no complicated lamination needed.Ingredients (makes about 20–25 pieces)Base Dough :

• Unsalted butter (softened to room temperature) — 50–60 g
• Corn oil (or neutral oil like vegetable/canola) — 25–30 g (adds extra crispiness without greasiness)
• Powdered sugar (糖粉) — 25–30 g
• Egg yolk — 1 large (about 20 g)
• Milk powder (全脂奶粉) — 15–30 g (more for stronger milk flavor)
• Low-gluten flour / cake flour (低筋面粉) — 150–165 g
• Baking powder — 1 g (optional, for lighter texture)
• Salt — 1 g (enhances flavor)
• Nuts (e.g., crushed peanuts, pine nuts, walnuts, or sesame seeds) — 40–50 g (toasted for aroma; pine nuts classic)

Milk Skin Topping :

• Egg white — 12–25 g (from 1 egg; adjust for thickness)
• Powdered sugar — 30–60 g (more for sweeter, thicker skin)
• Optional: 1–2 tsp cocoa powder / matcha / rose tea powder for flavored versions

Step-by-Step Instructions

1. Prepare the base dough
   • In a mixing bowl, soften butter until easily poked (room temp or microwave 10–15 sec bursts).
   • Add powdered sugar, salt, milk powder, and corn oil. Mix with a spatula or hand mixer on low until smooth and emulsified (no need to whip/cream heavily — just combine).
   • Add egg yolk. Stir until fully incorporated and creamy (like a thick paste).
   • Sift in low-gluten flour + baking powder. Add toasted crushed nuts.
   • Fold gently with spatula until crumbly (no dry flour visible). Do not knead — overworking makes it tough.
   • Texture check: Squeeze into a ball — it holds together but crumbles easily when pressed (classic shortbread "sand" stage).
2. Shape the base
   • Line a square/rectangular mold (e.g., 6-inch mousse ring or baking pan) with parchment paper.
   • Pour dough crumbs in. Spread evenly, then press firmly with spatula or bottom of a glass to compact (very important — prevents crumbling after baking). Thickness: about 1–1.5 cm.
   • Refrigerate 30–60 minutes (or freeze 20–30 min) to firm up for clean cutting.
3. Make the milk skin
   • In a clean bowl, add egg white + powdered sugar.
   • Do NOT use electric mixer (it over-aerates and makes it foamy/weak). Use a manual whisk or chopsticks.
   • Stir slowly and continuously in one direction until smooth, thick, and creamy like yogurt or soft buttercream (no peaks — just glossy and ribbon-like when lifted). Takes 5–10 minutes of patient stirring. Add flavor powder (cocoa/matcha) here if desired.
4. Assemble
   • Remove chilled base from fridge. Cut into strips/rectangles (e.g., 7 cm long × 1.2 cm wide) while still in one piece — do not separate yet.
   • Spread or brush milk skin evenly over the top surface (thicker layer for more "奶皮" effect).
   • Optional: Sprinkle extra nuts or sesame on top for decoration.
5. Bake
   • Preheat oven to 160–170°C (320–340°F), upper/lower heat (no fan for even browning).
   • Place on middle rack. Bake 20–30 minutes (watch color — edges golden, milk skin set and slightly browned).
   • If browning too fast, cover loosely with foil after 15 min.
   • Remove when done. Let cool completely in pan (it firms up and crisps as it cools).
6. Finish & Serve
   • Once fully cooled, separate pieces carefully.
   • The base should be ultra-crisp and crumbly; milk skin glossy and milky.
   • Store in airtight container — stays crisp 1–2 weeks (add silica packet in humid areas).

Quick Tips for Success

• Crispiness secret → Don't overmix dough; press firmly; bake low & slow.
• Milk skin texture → Manual stirring only — electric makes it bubbly/weak. Stop when it reaches thick yogurt consistency.
• Variations → Add cocoa/rose tea/matcha to milk skin for flavors; use pine nuts for classic Tianjin style.
• Common fixes → If base crumbles → pressed too lightly; if milk skin runny → under-stirred or too much egg white.
• Storage → Room temp airtight jar; avoid fridge (softens crisp).

This pastry is incredibly addictive — buttery, milky, crumbly perfection in every bite. Enjoy your homemade It's a nostalgic Northern Chinese favorite.