Cook butter in medium saucepan over medium heat until melted. Once melted, stir often until butter begins to brown and smell nutty, about 5 minutes. Remove from heat and add in pecans, sugar, cinnamon, and flour. Cool and reserve.
In a large bowl, whisk flour, baking powder, baking soda, cinnamon, salt, and sugar together.
Stir in melted butter, sour cream, milk, eggs, vanilla, and apples until smooth. Pour into prepared pan.
Sprinkle crumbled bacon on top of batter, followed by streusel.
Place pan in oven and bake for 30 to 45 minutes or until a toothpick inserted in the center comes out clean.
Optional: Add an extra degree of difficulty (and flavor) by pouring out half the batter in the cake pan, then adding a layer of streusel before adding the final half of batter and another layer of streusel on top--as pictured.
Preheat oven to 350 degrees F. Coat inside of a 9-inch fluted tube pan, such as for a Bundt Cake, with cooking spray.
Place bacon in large skillet and cook over medium-high heat, turn occasionally until evenly browned. Drain the bacon slices and crumble bacon.
Melt margarine in a small saucepan over medium heat; stir in the brown sugar and maple syrup. Bring the mixture to a boil; cook and stir until it begins to foam, about 1 minute. Remove from heat.
Mix white sugar and cinnamon in a sealable plastic bag; add 6 to 8 biscuit pieces at a time and shake until well coated. Pour any remaining sugar-cinnamon mixture into brown sugar mixture. Place saucepan over medium heat and cook and stir until sugar dissolves, for about 2 to 3 minutes.
Sprinkle 1/4 the bacon pieces in the bottom of the tube pan; pour in about 1/4 the brown sugar mixture. Arrange 1 layer of biscuit pieces in the tube pan; sprinkle in 1/4 the bacon pieces. Drizzle about 1/4 the brown sugar mixture over the biscuit pieces. Continue layering until all the ingredients are used, ending with a drizzle of brown sugar mixture.
Bake in the preheated oven until biscuits are cooked through, about 35 minutes. Allow to cool in pan, 10 to 20 minutes; invert onto a serving plate.
In a medium frying pan over medium-high heat, cook bacon, turning slices as needed, until browned on both sides and crisp. Transfer to paper towels to drain. When cool enough to handle, crumble bacon.
Cut each egg in half lengthwise; gently scoop out yolks and place in a bowl. Mash yolks with a fork, then stir in mayonnaise, green onions, mustard, and crumbled bacon until well blended. Add salt and pepper to taste.
Spoon or pipe about 1 tablespoon yolk mixture into the hollow of each egg-white half. Serve immediately or cover and chill up to 4 hours.