Whisk the flour, sugar, salt, and yeast together. Set aside. Heat the milk and butter together in the microwave until the butter is melted and the mixture is warm to the touch, between 100-110°F, 38-43°C. Pour the warm milk mixture into the dry ingredients. Add the egg. Using a handheld or stand mixer fitted with a dough hook or paddle attachment, or using a silicone spatula and mixing by hand, beat/mix the mixture until a soft dough forms. The dough is ready when it gently pulls away from the sides of the bowl. If the dough is pretty sticky, beat/mix in 2-4 extra Tablespoons of flour. (Keep in mind that you want the dough to remain on the softer side.)

Keep the dough in the stand mixer and beat for an additional 5 full minutes, or knead by hand on a lightly floured surface for 5 full minutes. (If you’re new to bread-baking, my How to Knead Dough video tutorial can help here.) If the dough becomes too sticky during the kneading process, sprinkle 1 teaspoon of flour at a time on the dough or on the work surface/in the bowl to make a soft, slightly tacky dough. Do not add more flour than you need because you do not want a dry dough. After kneading, the dough should still feel a little soft. Poke it with your finger—if it slowly bounces back, your dough is ready to rise. You can also do a “windowpane test” to see if your dough has been kneaded long enough: tear off a small (roughly golfball-size) piece of dough and gently stretch it out until it’s thin enough for light to pass through it. Hold it up to a window or light. Does light pass through the stretched dough without the dough tearing first? If so, your dough has been kneaded long enough and is ready to rise. If not, keep kneading until it passes the windowpane test.

Form the dough into a ball on your work surface. Cover it with a clean towel, aluminum foil, or plastic wrap, then let it rest for 30 minutes at room temperature. Alternatively, the ball of dough can rest in a covered and lightly greased mixing bowl.

After 30 minutes, use a rolling pin to roll the dough out into a 15×12-inch rectangle. Evenly spread the softened butter on top. Mix the sugar and cinnamon together and sprinkle it all over the buttered dough.

Grease a 9-inch round pie dish or 9-inch round cake pan with butter or nonstick spray.

See the video tutorial and my step-by-step photos above for a visual of this shaping step. Using a very sharp knife or a pizza cutter, cut the dough into six 2-inch wide strips. Roll up one strip and place it in the center of the pan. Coil the remaining 5 strips around the center roll, starting each strip at the end of the previous one to make one large cinnamon roll. Some of the filling may spill out as you pick up the strips, so just sprinkle it on top of the cake when you’re done shaping it.

Loosely cover the cake with aluminum foil or plastic wrap and allow it to rise in a relatively warm, draft-free environment for 1-2 hours or until double in size. (Tip: Rising at room temperature is usually fine, but on a particularly cold day, heat your oven to 150°F (66°C). Turn the oven off, place the shaped cake inside, and keep the door slightly ajar. This will be a warm environment for your dough to rise. After about 30 minutes, close the oven door to trap the air inside with the rising dough. When it’s doubled in size, remove from the oven.)

After the cake’s dough has doubled in size, preheat the oven to 350°F (177°C). Bake for 30-35 minutes or until golden brown. If you notice the top or edges browning too quickly, tent the cake with aluminum foil. While the giant cinnamon roll cake is baking, some spots may rise up more than other spots. That’s completely normal and expected from something this large. Simply remove the pan from the oven and, with the back of a spatula, press down the spots that are rising taller than others to help keep them even. Return to baking.

Remove the finished cinnamon roll cake from the oven and cool in the pan on a wire rack for 10 minutes. Meanwhile, make the icing.

Whisk the icing ingredients together. If you want a thicker icing, whisk in more confectioners’ sugar. If you want a thinner icing, whisk in more milk or cream. Drizzle all over warm cake and serve.

The cinnamon roll cake is best enjoyed the same day it’s made, but will remain fresh covered tightly for up to 4 days in the refrigerator.