Preheat oven to 375 degrees Fahrenheit. Grease a round eight-inch cake pan.

In bowl, toss together flour, sugar and cinnamon. Pour oil over mixture, tossing with fork or fingers until a crumbly mixture is formed. Set aside.

In bowl of electric stand up mixer or using hand-held mixer, beat oil with eggs until well combined and light coloured. Beat in granulated and brown sugars; beat for two minutes. Beat in vanilla.

In separate bowl, combine flour, baking powder and salt. Fold in flour mixture alternately with pear nectar, making three additions of flour and two of pear, ending with the flour mixture.

Scrape batter into prepared pan. Arrange pear slices on top of batter in a concentric circle. Sprinkle streusel over until pears are completely covered.

Bake in centre of preheated oven for 35–40 minutes or until cake tester inserted in centre of cake comes out clean. Cool in pan on rack. Once cool, invert onto plate and then re-invert so that streusel and pears are on top.