Preheat your oven to 325℉.Gather all of your ingredients and measure your flour and sugar using the "Spoon and Sweep Method". The 'spoon and sweep' method is the most accurate way to measure flour, aside from weighing it on a kitchen scale. Use your spoon to gently stir and fluff the flour in its container, then scoop the flour directly into the measuring cup, using the straight edge of the spoon to sweep away the excess flour once the cup is full. Prepare a 9x5" baking loaf pan by spraying lightly with cooking spray (or use butter) and line using parchment paper that extends slightly over the side of the pan. Dust lightly with flour and gently tap out the excess. This will ensure that your finished apple bread can easily be removed from the pan.
In the bowl of your stand mixer (or a large bowl, if using a handheld mixer), cream the butter and sugar for the bread ingredients. Once the mixture is pale yellow in color, about 2 minutes, add in the eggs, one at a time and mix until the batter is no longer glossy.
In a small bowl, stir the baking soda into the sour cream to dissolve, then set aside. Incorporate the flour and salt until well blended, then add the sour cream and vanilla extract into the batter, scraping down the sides of the bowl as needed. The batter will be pale and creamy.
Prepare the streusel topping by blending together the butter, sugar, flour, cinnamon and nuts. The mixture will have a texture similar to wet sand.
Peel and quarter the apples, cutting out the core, and then dice into small pieces. Toss gently with a little lemon juice to prevent the apples from oxidizing (browning).
Using a rubber spatula, fold the diced apples into the batter. Pour the batter into the prepared loaf pan.
Crumble the topping evenly over the surface of the batter and bake in the preheated oven for about 1 hour. A toothpick inserted into the center of the bread should come out clean. If using a thermometer, the internal temperature should be between 190-200℉.
Allow the bread to cool slightly before removing it from the loaf pan.
While the bread is cooling, preparing the glaze. Reduce the apple cider in a small pan over medium-high heat by half, about 7-8 minutes. This helps to concentrate the apple flavor. Add the powdered sugar, salt, cinnamon and heavy cream to the bowl of a stand mixer, then drizzle in the warm, reduced cider. Mix at high speed until all of the ingredients are combined. If you'd prefer a thinner glaze, add in a little more cream.
Drizzle the cider glaze over the top of the cooled bread. Slice and serve.
Store in an air-tight container fitted with a lid.