For the stewed apples or pears: Peel two small or medium-sized pears or apples and dice into 1/2 inch chunk pieces. Place in a small pot and heat to medium/ medium-high. Once it starts cooking, stir the fruit every few minutes for about 10 minutes. After 10-12 minutes the fruit should be softened. Turn of the heat and set the fruit aside. Note: if you're using apples, then add a tablespoon of water into the pot since they have a lower water content than pears.
Grease the cake or bundt tin with butter (use a pastry brush to make sure you get into all the nooks and crannies). Lightly dust with flour (about 1/2 tablespoon). Preheat the oven to 350°
In a large mixing bowl, cream the butter with the sugar on medium high with a handheld mixer. Mix until the ingredients get paler in color (2-3 minutes).
Add in the eggs, vanilla extract, pears, and yogurt. Mix on medium until all combined.
Add in the flour, baking powder, baking soda, and salt. Mix until just combined.
Pour batter into greased tin. Place in oven and bake until a toothpick or knife inserted into the center of the cake comes out clean (45-48 minutes).
Remove from oven and let cool for 15 minutes. Take a cooling rack and place on top of cake. Gently flip the cake over so that the cooling rack ends up on the bottom. Gingerly remove the tin. The tin should come off easily if properly greased beforehand.
Sprinkle with powdered sugar and enjoy! This cake keeps for 2-3 days wrapped in plastic wrap but it can also be frozen.