In a medium bowl, whisk together rice flour and baking soda.
In a large bowl, whisk together date jam, sugar and water until sugar is dissolved. Gradually add rice flour mixture and mix until smooth. Gradually add oil and mix until well combined.
Line two 6" cake pans or one 8" cake pan with plastic wrap. Divide batter between the two 6" cake pans or pour all of it into one 8" cake pan. Cover pans with aluminum foil.
This works for the 6" cake pan only. Place steam trivet in Instant Pot or Pressure Cooker. Add 1 cup water. Place cake pan on trivet. Cover and select "Pressure" cook mode. Set timer for 30 minutes.
Natural release pressure. Carefully remove cake pan from Instant Pot. Let cool.
Serve at room temperature by cutting into wedges or slices. Keep extras in the refrigerator or freeze for up to one month. To reheat cold sticky rice cake, cut into wedges or slices and toast in toaster oven. Alternatively, dip slices in beaten egg and pan fry with a little oil.
Set up teamer with two tiers. Bring water to boil in steamer pot. Place one cake pan on each steamer tier. Cover and steam for one hour.
Carefully remove cake pan from pot. Let cool.
Serve at room temperature. Keep extras in the refrigerator or freeze for up to one month. To reheat cold sticky rice cake, cut into wedges or slices and toast in toaster oven. Alternatively, dip slices in beaten egg and pan fry with a little oil.
Adapted from Florence Lin's Complete Book of Chinese Noodles, Dumplings and Breads. If you cannot find date jam or don't want to make it yourself, Auntie Florence suggests using 1 1/2 cup dark brown sugar instead of the date jam and sugar.