- Sieve all purpose flour , cornflour , spice powders , salt and baking soda together ,twice and set aside. 
- In a mixing bowl , add 2 eggs , brown sugar , granulated sugar and whisk well. 
- Add milk , pumpkin puree , vanilla essence , oil and whisk well all together so that everything mixes well. 
- Now take sieved dry ingredients in a bowl and slowly add wet ingredients part by part to the flour mixture. 
- With a spatula gently mix everything carefully such that no lumps are formed. 
- Finally , add ½ cup of walnut and stir into the cake batter gently. 
- Grease the cake tin / loaf pan and pour the batter. 
- Take a wide pressure cooker , add sea salt (crystal salt)  into cooker and evenly spread salt. Keep a heat proof stand on sea salt and place cooker on a high flame on a stove top. This is similar to preheating in oven. Alternatively , you can bake cake in a preheat oven at 180 deg celsius and bake for 25 to 30 minutes. 
- After 6-8 minutes, salt to becomes sufficiently hot then immediately reduce the flame to low heat /sim and place cake tin inside the pressure cooker. 
- Remove gasket (rubber ring)  from pressure cooker lid and securely close it.  
- Don't put vent weight( whistle) on the pressure cooker. 
- Cook on a low heat for about 35-45 minutes , till toothpick inserted comes out clean. 
- Remove the cake tin from pressure cooker and allow it to cool completely. 
- Invert the cake tin on a plate , tap it gently  and remove the cake . 
- Wrap the cake with clingfilm and let it sit overnight before serving. The flavors meld well and tastes delicious when served on following day .   
- Serve cake at room temperature either for breakfast or with tea. Also you can serve slice of cake with scoop of ice cream.