Preheat the oven to 350 degrees F. Grease or line with parchment paper a 9×5 bread pan.
Prepare the diced apples by adding 1 tablespoon sugar with 1/2 teaspoon cinnamon. Stir together. Add in the diced apples and toss to coat all the apples. Set aside.
In a medium mixing bowl, combine the flour, salt, baking powder and baking soda. Whisk together and set aside.
In a separate large mixing bowl, combine the eggs and sugar. Beat together with a hand mixer or whisk until fully combined. Add the Greek yogurt, vanilla extract, and oil. Mix until well combined. Add the flour mixture into the wet ingredients and stir until just combined. Be careful not to over mix.
To make the cinnamon streusel, add 1/3 cup flour, 1/4 cup brown sugar and 1/2 tablespoon of cinnamon to a medium bowl. Stir together. Add the softened butter and mix together with a fork your hands until the ingredients are fully combined.
Scoop half the vanilla batter into the loaf pan, and gently spread out. Evenly add half of the diced apples over the batter. Sprinkle over half of the streusel over the apples. Scoop the remaining batter over the streusel and carefully spread out. Top with remaining diced apples and then streusel.
Bake the apple loaf for 50-60 minutes or until the batter is fully set and a toothpick comes out clean. Remove from the oven and let cool.
While the bread is cooling, make the glaze by whisking the powered sugar, milk and vanilla extract together until smooth. The glaze should be thick but you can a splash more milk if needed.
Once the apple bread is cooled, drizzle the glaze on top of the loaf and enjoy!