- Make the cream cheese filling: In a stand mixer fitted with paddle attachment, combine cream cheese, vanilla, lemon juice, and salt. Mix, scraping down bowl sides several times. Add sifted sugar and continue to mix until combined. Set aside.
- Make the pumpkin filling: In a large bowl, whisk first six dry ingredients together. In a separate bowl, add remaining wet ingredients and mix until combined. Fold dry ingredients into wet ingredients, mixing just until combined. Do not overmix. Set aside.
- Make the dough: In a stand mixer fitted with dough hook, combine flour, yeast, water, butter, eggs, and vanilla. Mix on medium speed until dough has smooth exterior and is not sticking to sides of bowl, about 8 minutes. Add salt and sugar. Mix until combined and smooth, about 5 minutes. Place dough on a greased surface, rounding under edges to make a smooth ball. Spray dough with pan spray and place on a sheet tray. Wrap with plastic wrap and refrigerate overnight. Before using, let dough sit at room temperature for 1½ hours.
- Make the streusel: In a medium bowl, stir first five dry ingredients together. Cut in butter until mixture resembles fine crumbs. Toss in coconut and pumpkin seeds and mix by hand to form a crumb topping.
- Assemble the babka: Cut dough in half and flatten each half. Roll out on lightly floured surface until both dough halves are very thin and about 9×12 inches in size.
- Pipe four rows of cream cheese filling on one half of dough. After cream cheese, spread thin layer of pumpkin filling, leaving a ½-inch border all around. Roll up like a jelly roll down short side, then use hands to make sure roll is smooth and evenly sized. Repeat with other half of dough.
- Once both doughs are filled, place side by side. Cut off ends of each so they are smooth and even in length. Cut each log in half lengthwise and then twist the two pieces together. Place each twist side by side in greased loaf pan and let rise 2½ hours.
- Preheat oven to 350 degrees.
- Top risen dough with coconut-pumpkin seed streusel, using your hands to make large “crumbs” by squeezing the mixture together. Bake, with no fan and with a pan of ice cubes in bottom of oven to create steam, for about 40 minutes. The babka is done when a toothpick can be inserted with no resistance. If dough is getting too dark before finished, cover with foil.