Prep the Tin – Preheat oven to 175°C (350°F). Grease a 26x9 cm bundt tin really well, making sure to get into all the grooves, then dust lightly with flour.
Mix Dry Ingredients – In a large bowl, whisk together flour, baking powder, baking soda, salt, and spices.
Mix Wet Ingredients – In another bowl, beat together sugars, oil, eggs, pumpkin purée, and vanilla until smooth.
Combine – Fold the dry ingredients into the wet until just combined. Don’t overmix.
Bake – Pour batter into the prepared tin, smoothing the top. Bake for 55–65 minutes, until a skewer inserted into the centre comes out clean.
Cool – Let the cake cool in the tin for 15 minutes, then carefully turn it out onto a wire rack to cool completely.
Make the glaze: In a medium bowl, beat together the cream cheese and butter until smooth and creamy.
Add the vanilla and half of the icing sugar. Mix on low speed until combined, then add the rest of the sugar.
Beat until thick, smooth, and fluffy. If it’s too thick to spread or drizzle, add a teaspoon of milk or cream at a time until it loosens just slightly.
Spoon or drizzle over the cooled bundt cake, letting some drip down the sides but keeping most of it thick and luscious on top.