Make the strawberry filling. Combine strawberries, lemon juice, and sugar in a medium saucepan. Cook over medium heat until the strawberries begin to soften, about 20 minutes. Mash the strawberries occasionally with a fork or wooden spoon to help release the juices and allow the strawberries to break down.
When the strawberries have broken down and the sauce becomes slightly thickened, mix together cornstarch and water in a small bowl to create a slurry, then pour into the strawberry sauce. Mix together and cook for another 5 minutes, until the sauce thickens and becomes paste-like (akin to strawberry jam), about 3-5 minutes. Set aside to cool.
Add bread flour and all purpose flour to a large mixing bowl. Whisk together and remove 3 cups of the flour mixture into the bowl of a stand mixer. (you will have 3 cups of flour in the bowl of a stand mixer and 3 cups of flour in a large bowl).
To the bowl of a stand mixer, add 1 cup whole milk and mix until well combined (a shaggy dough will form). Cover, and let rest for 30 minutes.
To the large bowl with the remaining flour mixture, add ½ cup granulated sugar, salt, cinnamon, and nutmeg. Whisk to combine and set aside. In a small bowl, microwave ½ cup milk until warm, about 105-100 degrees F. Add yeast and remaining 1 tablespoon granulated sugar. Whisk together. Let stand until foamy, 5 to 10 minutes. Then add eggs and vanilla extract. Whisk until well combined. To the stand mixer bowl, add remaining flour mixture and yeast/milk mixture. Using your hands, gently knead ingredients together until a dough forms, focusing on incorporating everything into one cohesive dough, about 1 minute. Return bowl to stand mixer and fit with the dough hook attachment. Beat at medium-low speed until dough becomes smooth, about 2-5 minutes.
Begin adding butter 2 tablespoons at a time, beating until there are no butter streaks left after each addition, 45 seconds to 1 minute. Continue to beat until smooth, about 5 minutes. Stop mixer and perform the windowpane test. (Pinch off a piece of the dough, and gently stretch it between two fingers. If you can see through it, the dough is ready. If the dough breaks, continue to beat for 2 minutes more and then repeat the windowpane test.)
Spray a large bowl with cooking spray. Place dough in bowl. Cover with plastic wrap, and let rise in a draft-free warm place (75°F/24°C) until doubled in size, about 1 hour and 30 minutes. Turn out dough onto a lightly floured work surface, and gently stretch into an 18x12-inch rectangle. (Try to avoid using a rolling pin to keep as much air in the dough as possible.)
Remove 3 tbsps of the strawberry filling into a bowl and set aside. Use the back of a spoon to spread remaining filling onto dough. Using a sharp kitchen knife or pizza cutter, cut dough into 12 equal strips. Roll each strip into a tight spiral and place, spiral side down, into a prepared baking dish. Cover and let rise until puffy, 25 to 40 minutes (second rise).
Preheat oven to 350°F (180°C). Bake in the preheated oven until the tops of the rolls are golden brown, about 30-35 minutes.
For the icing: In a medium bowl, cream together cream cheese and butter with a handheld mixer at medium speed for 1 to 2 minutes, until smooth. Add confectioners’ sugar, add heavy cream, and lemon zest and continue to mix until fully combined and smooth, about 1-2 minutes. Add vanilla bean paste and the reserved strawberry filling; beat until well combined, about 20 seconds.
Spread icing onto warm cinnamon rolls. (If you prefer your icing to be thick like that on cake, let cinnamon rolls cool for 30 to 45 minutes before adding the icing.)
Notes
Storing Leftovers and Making AheadStoring: The best way to store leftover cinnamon rolls is in an airtight container in the refrigerator. Because of the cream cheese in the frosting, you'll want to store them in the fridge. If you like warm rolls, pop them in the microwave for a few seconds prior to eating. The icing may melt a bit but with cinnamon rolls, the messier the better in my book!Making ahead: You can make the dough ahead of time. Prepare it as instructed and when it's time for the dough to rise, cover it and place it into the refrigerator overnight. (do not exceed 24 hours) Let the dough sit at room temperature for about 30 minutes, then resume with preparing as per the recipe card.Tips for the Best Cinnamon Rolls
Use a kitchen scale to measure your ingredients. Specifically, you'll want to weight everything in grams. When you go to the recipe card, switch the units to metric and you'll get all of the gram measurements there. This ensures the most consistent results.
Cut the cinnamon rolls with unflavored dental floss. Of course a serrated knife or sharp knife will work, but you get the cleanest cut with dental floss! It sounds crazy but trust me on this one!
Make sure that your yeast is active! Expired yeast will not rise. When you dissolve the yeast in the milk, if it doesn't become nice and foamy, it's 9/10 probably bad. Don't use it, you'll need to get a new pack.
Roll each roll nice and tight! This will give you those perfect spirals when they bake up in the oven.