Well grease and then flour a 10 inch bundt cake pan. Make sure to grease and flour it well or the cake might not come out perfectly.
In a large bowl, beat together butter and cream cheese until completely smooth.
**It is very important the butter and cream cheese are both at room temperature before starting otherwise the cream cheese will separate in the baking process and your cake will be done in some areas and not done in others.**
Add in the sugar and beat for about 2-3 minutes or more or until light and fluffy.
Beat in the extracts and the buttermilk. (Check notes if you don't have buttermilk on hand.)
Slowly add the eggs beating after each addition.
Add all of the flour and mix until combined.
Separate the mixture in two. Pour the white mixture into the greased and floured bundt cake.
Pour the marshmallows (amount to your desired preference) on top and swirl the marshmallows throughout with a long skewer.
Dye the remaining mixture green and then pour on top of the white mixture and marshmallows.
Swirl the two layers gently to desired swirl amount.
Place in the oven and then start your oven preheating to 325.
Start the timer as soon as you place the cake in the oven (not after it is done preheating) for 60 minutes.
Check it after 60 minutes by inserting a toothpick into the center. If it comes out clean, remove the cake.
If not, return the cake to the oven for another 10-20 minutes.
My cake took 75 minutes total.
Remove and let cool. Invert the cake onto a cake stand or large plate and let cool.
Meanwhile, beat together the powdered sugar, cream cheese, butter, and vanilla. Add milk to get to your desired consistency.
Pour the glaze over the mostly cooled cake.
Garnish with desired amounts of marshmallows.
Notes
*If you don't have buttermilk, mix a scant 1/4 cup milk with 1 tsp. vinegar and let sit for about 5 minutes and then add to mixture. **If you opt for food dye drops, it will probably take a lot more than 1/4 tsp.