Prepare all the dry ingredients for the cake. Combine flour, salt, baking soda, cinnamon, nutmeg, and all spice in a bowl and mix.
Prepare all wet ingredients in a separate bowl: brown sugar, oil, 2 tablespoons melted butter (leave about 1 tbsp to brush the inside of the pot/cooker), yogurt, vanilla extract, and mix well. Add beaten eggs slowly while mixing.
Combine wet ingredients with the dry ingredients and mix. Add shredded carrots and chopped walnuts.
Brush melted butter along the insides of the rice cooker's pot. Pour batter and press cook. Once it pops to warm, wait for about 10-15 minutes and press button back to cook. One might also need to flip the cake upside down using a plate to cook the other side. Depending on how hot the cooker gets, it might take a few more presses of the cook button for the cake to be fully ready. Make sure to check with a toothpick or a fork to see if it comes out clean. Once done, put on a rack to cool.
While the cake cools, make the cream cheese frosting. In a bowl add softened cream cheese, confectioner's sugar, half a cup of yogurt, vanilla extract and lemon juice and mix well.
Once cake has cooled down, top it with the cream cheese frosting and serve.
