Creating the Gooey Almond Croissant Sourdough Coffee Cake can be straightforward if you follow these simple steps:

1. Prepare the Dough: In a large bowl, mix the sourdough starter, flour, granulated sugar, and salt until combined.
2. Incorporate Butter: Add in ¾ cup of softened butter and the eggs. Mix until a dough forms.
3. Kneading: Turn the dough onto a floured surface and knead for about 5 minutes until smooth and elastic.
4. First Rise: Place the dough in a greased bowl, cover, and let rise for about 1 hour, or until doubled in size.
5. Rolling Out: Once risen, turn out the dough onto a floured surface. Roll it out into a rectangle, about ½-inch thick.
6. Butter Layering: Spread the remaining ¼ cup of softened butter evenly over the dough.
7. Folding the Dough: Fold the dough into thirds, similar to a business letter. Roll out again into a rectangle; repeat this folding process two more times.
8. Second Rise: Cover the dough and let it rise for another 30 minutes.
9. Prepare the Filling: In a bowl, combine the almond paste and almond extract.
10. Fill the Dough: Roll out the final dough again, spread the almond filling evenly, and sprinkle sliced almonds on top.
11. Shape the Cake: Roll the dough tightly to form a log, and place it in a greased loaf pan.
12. Final Rise: Cover and let rise for 30 minutes.
13. Preheat Oven: Preheat your oven to 350°F (175°C).
14. Bake the Cake: Bake for 25-30 minutes or until golden brown. A toothpick should come out clean.
15. Cool the Cake: Allow the cake to cool in the pan for 15 minutes, then transfer to a wire rack.
16. Prepare Glaze: Mix the powdered sugar with milk to form a smooth glaze.
17. Glaze the Cake: Drizzle the glaze over the top of the cooled cake.

Following these steps will guide you through baking this incredible coffee cake without a hitch!