Preheat the oven to 325°F. Line a 13×9-inch baking pan with parchment paper.
In a large mixing bowl, whisk together flour, baking soda, cinnamon, apple pie spice, and salt. Set aside.
In another bowl, beat the eggs lightly. Add oil, brown sugar, granulated sugar, and vanilla. Mix until smooth.
Gradually stir in the dry ingredients until just combined. Do not overmix.
Fold in the apples and pecans with a spatula. The batter will be thick and apple-heavy.
Spread batter evenly into the prepared pan.
Bake for 1 hour 15 minutes, or until a toothpick inserted in the center comes out clean.
Cool the cake in the pan on a wire rack while preparing the glaze.
For the glaze: In a saucepan, melt butter. Add both sugars and cream, stirring constantly over low heat for 5 minutes.
Increase heat to high, boil for 2 minutes, then remove from heat. Let cool for 5–7 minutes until slightly thickened.
Spoon glaze evenly over the warm cake.
Sprinkle with flaky sea salt.
Allow cake to cool completely before slicing with a sharp knife.