These Bundts are a mini take on everybody's favorite bake-and-flip dessert. They are filled with cherries and accompanies by a sour-cherry-and-vanilla sauce.
Preheat oven to 375 degrees. Generously butter and flour a 6-cake mini Bundt pan (with an 8-ounce capacity and 3 3/4-inch diameter).
Whisk together flour, salt, baking powder, and baking soda. In the bowl of an electric mixer with a paddle attachment, beat butter and sugar until light and fluffy, about 3 minutes. Beat in eggs, one at a time, and vanilla. Add flour mixture in two parts, alternating with sour cream (take care to not overmix).
Fill a disposable pastry bag with one-third of the batter; cut its tip to make a 1/2-inch opening. Pipe batter into the bottom of the molds to about 3/4 inch high. Using a mini offset spatula, smooth batter until even. Scatter half of the pineapple over top. Repeat with more batter and remaining pineapple, and finish with remaining batter; smooth tops. Bake for 19 to 21 minutes or until a wooden skewer inserted comes out with loose crumbs attached. Cool for 3 minutes and immediately invert cakes to remove from molds. Allow cakes to cool completely.
Meanwhile, make the pineapple syrup: Bring sugar and juice to a boil and simmer for 3 minutes or until slightly thickened. Allow to cool to room temperature.
Trim tops of cakes so that they are even (they should be 2 1/2 inches high). Invert cakes and generously brush outsides with syrup.
To serve, spoon some cherries into center hole of each cake and a little bit of sauce around the perimeter. Top each cake with a pineapple flower to conceal cherries underneath.