1) Preheat oven to 350-degrees. Grease an 8" Springform pan. Whisk together the molasses, sour cream, brown sugar, eggs, grated ginger, and lemon zest. melt the butter and whisk into the mixture.
Twice sift the flours, baking powder, salt and ginger powder. Fold into the warm batter, whisking gently if necessary to break down any residual lumps of flour. The batter will be fairly runny.
Tip it into a well-greased 8-inch springform pan and bake in the center of oven for 35-45 minutes, or until a skewer comes out clean.
Soak the pistachios in boiling water for 2 minutes, then use a very sharp knife to peel away the skins. Pat dry and chop finely. Sprinkle over the top of the cake and serve.
2) Dissolve 1/2 cup of the sugar with the water and boil until it reaches 234-degrees on a candy thermometer. This takes approximately 8 minutes. Then add the honey and cook to a dark caramel, which will take an additional 8-10 minutes. Be careful that it does not burn, and remember that the residual heat will continue to cook it once you remove it from the heat.
Meanwhile, in a sauce pan bring the milk and cream to a boil. In a mixing bowl, whisk egg yolks with the remaning sugar. Slowly temper the egg yolks while whisking then add everything to the pot. Mix in the caramel and stir over a very gentle heat until it thickens. You should be able to draw a clear line through the custard on the back of a spoon.
Remove the pan from the heat and cool in a sink of cold ice water, stirring from time to time. When the custard is completely cold, pour it into an ice cream maker and churn according to manufacture's instructions.