Preheat oven to 350°F (180°C) and grease the bottom and sides of a 9-inch spring form pan with baking spray or butter. Set aside.
Using a food processor, blender, or immersion blender, purée half of the apricots with the lemon juice and set aside.
Quarter the remaining apricots and set aside.
In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugar together at medium-high speed until light and fluffy, about 4–5 minutes.
Add eggs, one at a time. Then add vanilla extract and beat until combined.
In a small bowl, combine flour, baking powder, cinnamon, and salt. Add to the mixture and beat until just combined.
Add puréed apricots to the batter and beat until just combined.
Transfer batter to the prepared spring form pan. Distribute the quartered apricots evenly on top of the batter and bake for 55–60 minutes, or until a skewer inserted in the center comes out clean with only a few crumbs attached.
Let cool, then dust with powdered sugar.