Preheat oven to 325 degrees F. Liberally grease and flour a 10 cup Bundt pan. I recommend using a generous layer of shortening and dust it lightly with flour. You really want this well greased!
Sift together the flour, sugar, salt, baking powder, baking soda, and cream of tartar. Meanwhile, combine the Irish creme coffee creamer and the Bailey's.
Cream the butter in a large bowl with an electric mixer until smooth, about 1 minute. Beat in the vanilla and butter extracts, followed by the eggs, one at a time. Add 1/3 of the flour/sugar mixture, beating on low speed. Add in 1/3 of the Bailey's mixture, beating well to incorporate. Repeat with the flour mixture, followed by the Bailey's mixture, until a thick batter forms.
Pour the batter into the prepared pan and smooth out the top. Bake for approx. 50-60 minutes or until a toothpick inserted near the center comes out clean or with moist crumbs. Cool for about 15 minutes, then poke holes all over the cake using a skewer or cake tester.
In a small saucepan, combine the sauce ingredients and stir lightly over low heat until bubbly and melted. Pour the butter sauce evenly over the top of the cake, allowing the sauce to seep into the holes of the cake. Cool completely. Using a butter knife, gently run the knife around the edge of the pan to release the cake. Dust with powdered sugar.