More infusing vodka
For pumpkin I would do the same thing as I do for cranberry.
Fresh cranberry doesn't taste like cooked cranberry and I like the cooked cranberry flavor better. So what I do is put the berries in a 1 liter canning jar filling it 3/4 of the way. Then cover with vodka. Then I pour into a blender and blend. Then I pour it back into the jar and top off with vodka. After sitting for two weeks I process the unopened jar in a hot water bath for 10 minutes. This cooks the berries. Then I let sit another two weeks and filter.
For pumpkin I would do basically the same thing and see how it comes out. You can let one jar stay raw and one through the water bath and see how each tastes.
Banana works really, really well! Use fresh bananas that are just a little speckled with brown but no bruises. Fill a 1 liter jar around 3/4 full with whole bananas and then stick a knife in the jar and roughly cut up the bananas. The jar should end up 1/2 full of cut up banana. Immediately fill the jar with vodka to the brim... to the point it just barely overflows and seal. Then shake. tap the jar on the counter gently to force all the air bubbles to the top and then fill to the brim again with vodka. The idea is to get out ALL the air to prevent oxidation or else it will turn yucky brown color. If you get out all the air it will stay a creamy clear. Banana only needs to sit for 2 weeks to get all the flavor out. When done filter it and put in smaller jars so that there is no air and let sit for 1-2 weeks until it settles out. Carefully decant and filter. At this point it is ready. You can add sugar syrup to make a liqueur or serve plain as a straight infusion. I have found that banana tastes better fresh and it starts to lose flavor as it ages.