In a large bowl combine flour, sugar, baking powder and salt.
Make a well in the middle, and add in oil, whisked eggs, juice and vanilla.
Mix all ingredients with a spatula or wooden spoon until combined. Do not overmix. The batter will be thick but pourable.
Next, peel and core apples and cut into thin wedges, about 1/8" thick. You should have about 5 cups.
Combine apples with 1/4 cup sugar and 2 teaspoons cinnamon and set aside.
Grease 12-cup bundt pan with melted butter/oil and a light coating of flour or a nonstick spray (my favorite) and set aside.
Spoon a little less than 1/3 batter in pan. Add a layer of 1/2 apple mixture, add another 1/3 batter. Follow with other half apple mixture and the rest of the batter. Don't worry too much if the layers aren't even or if the apples are totally covered, the cake will spread and it will taste great!
Bake for 70-75 minutes or until toothpick comes out clean. Let cool slightly (15 minutes) before inverting it onto a wire cooling rack to finish cooling.
Mix confectioners sugar with enough boiling water or lemon juice to make a thick but runny glaze. Drizzle all over your cooled cake cake!
Notes
This cake is great to make ahead and tastes even better after a day or two! Store covered at room temperature for up to 4 days.