Preheat the oven to 350°F.
Peel the pears. Dice one pear into bite-size cubes and cut the second one into ⅛” slices. Set aside.
Melt butter in the microwave for 30 - 40 seconds. Brush a 9” springform cake pan with some melted butter. Reserve about 1 teaspoon to brush on the pears later.
Add the remaining melted butter to a medium mixing bowl along with mascarpone, eggs, and vanilla extract. Beat with a whisk until smooth.
In a small mixing bowl, add flour, baking powder, salt, and sugar. Reserve about 1 teaspoon of sugar to sprinkle on top later. Mix the dry ingredients together with a whisk until evenly distributed.
Add the dry ingredient mixture to the wet ingredient in the medium mixing bowl and fold with a spatula until combined. Fold the diced pears into the batter.
Transfer cake batter into the prepared cake pan, use the spatula to flatten the top down. Add sliced pears on the top. Brush pears with the reserved butter and sprinkle the reserved sugar over the top.
Bake for 45 minutes until the top is light brown and an inserted toothpick in the middle comes out clean with just a few crumbs on it.
Allow cake to cool completely before unmolding from the cake pan.