Preheat oven to 325 degrees F.
Butter and flour four 9-inch round cake pans then line bottom with a round of parchment paper. Butter the parchment.
In a mixing bowl, whisk together flour, baking soda and salt until well blended, then set aside till needed.
Mash bananas with 1 tsp lemon juice.
In the bowl of an electric stand mixer fitted with the paddle attachment, whip together the butter, 2 Tbsp vegetable oil, granulated sugar and light brown sugar on medium-high speed until pale and fluffy.
Add in the remaining 2 Tbsp of vegetable oil then add in eggs one at a time.
Add in the vanilla and mashed bananas.
With mixer set on low speed, slowly add the flour mixture alternating with Greek yogurt in 3 separate batches, beginning and ending with flour mixture and mixing just until combined after each addition. Don't overmix!
Divide the batter evenly among prepared cake pans and spread batter into an even layer.
Bake the cakes in the preheated oven for 30 - 35 minutes. Or until toothpick inserted into c the enter comes out clean. Allow the cakes to cool completely before frosting.