In a large mixing bowl, beat together eggs and sugar until fluffy and pale in color; about 3 minutes.
3 large eggs, 2 cups granulated sugar
Add butter, oil, and finally vanilla, blending between each ingredient. Add in buttermilk and Greek yogurt until well blended.
12 tbsps. unsalted butter, 1/3 cup canola oil, 2 tsps. vanilla extract, 1/2 cup buttermilk, 1/2 cup plain Greek yogurt
In a separate bowl, sift together flour, baking powder, baking soda, and salt. Slowly add dry ingredients into wet ingredients and mix on low speed until blended. (Do not overmix.)
3 cups all-purpose flour, 1 tsp. baking powder, 1/2 tsp. baking soda, 1/2 tsp. table salt
Spoon batter into Bundt pan over pineapple slices. Shimmy the Bundt pan on countertop to get air bubbles to rise, and to level the batter.
Bake for 55-60 minutes, or until a toothpick comes out mostly clean, with some moist crumbs.
Let the cake cool on a cooling rack for at least an hour. Carefully flip the Bundt pan over on a plate or cake stand. Serve warm or at room temperature.