diff --git a/openeo/rest/_datacube.py b/openeo/rest/_datacube.py
index fce6f717c..b63672d97 100644
--- a/openeo/rest/_datacube.py
+++ b/openeo/rest/_datacube.py
@@ -113,7 +113,13 @@ def from_node(self):
         # _FromNodeMixin API
         return self._pg
 
-    def _build_pgnode(self, process_id: str, arguments: dict, namespace: Optional[str], **kwargs) -> PGNode:
+    def _build_pgnode(
+        self,
+        process_id: str,
+        arguments: Optional[dict] = None,
+        namespace: Optional[str] = None,
+        **kwargs
+    ) -> PGNode:
         """
         Helper to build a PGNode from given argument dict and/or kwargs,
         and possibly resolving the `THIS` reference.
diff --git a/openeo/rest/datacube.py b/openeo/rest/datacube.py
index 462a92fc6..6a9242f3a 100644
--- a/openeo/rest/datacube.py
+++ b/openeo/rest/datacube.py
@@ -196,13 +196,13 @@ def __init__(self, graph: PGNode, connection: 'openeo.Connection', metadata: Col
         self.metadata = CollectionMetadata.get_or_create(metadata)
 
     def process(
-            self,
-            process_id: str,
-            arguments: dict = None,
-            metadata: Optional[CollectionMetadata] = None,
-            namespace: Optional[str] = None,
-            **kwargs
-    ) -> 'DataCube':
+        self,
+        process_id: str,
+        arguments: Optional[dict] = None,
+        metadata: Optional[CollectionMetadata] = None,
+        namespace: Optional[str] = None,
+        **kwargs,
+    ) -> "DataCube":
         """
         Generic helper to create a new DataCube by applying a process.
 
@@ -961,14 +961,21 @@ def _get_geometry_argument(
 
     @openeo_process
     def aggregate_spatial(
-            self,
-            geometries: Union[shapely.geometry.base.BaseGeometry, dict, str, pathlib.Path, Parameter, "VectorCube"],
-            reducer: Union[str, PGNode, typing.Callable],
-            target_dimension: Optional[str] = None,
-            crs: str = None,
-            context: Optional[dict] = None,
-            # TODO arguments: target dimension, context
-    ) -> 'DataCube':
+        self,
+        geometries: Union[
+            shapely.geometry.base.BaseGeometry,
+            dict,
+            str,
+            pathlib.Path,
+            Parameter,
+            VectorCube,
+        ],
+        reducer: Union[str, PGNode, typing.Callable],
+        target_dimension: Optional[str] = None,
+        crs: str = None,
+        context: Optional[dict] = None,
+        # TODO arguments: target dimension, context
+    ) -> VectorCube:
         """
         Aggregates statistics for one or more geometries (e.g. zonal statistics for polygons)
         over the spatial dimensions.
@@ -984,16 +991,24 @@ def aggregate_spatial(
             .. note:: this ``crs`` argument is a non-standard/experimental feature, only supported by specific back-ends.
                 See https://github.com/Open-EO/openeo-processes/issues/235 for details.
         """
-        # TODO #279 aggregate_spatial should return a VectorCube, not a DataCube
         valid_geojson_types = [
             "Point", "MultiPoint", "LineString", "MultiLineString",
             "Polygon", "MultiPolygon", "GeometryCollection", "Feature", "FeatureCollection"
         ]
         geometries = self._get_geometry_argument(geometries, valid_geojson_types=valid_geojson_types, crs=crs)
         reducer = self._get_callback(reducer, parent_parameters=["data"])
-        return self.process(
-            process_id="aggregate_spatial", data=THIS, geometries=geometries, reducer=reducer,
-            **dict_no_none(target_dimension=target_dimension, context=context)
+        return VectorCube(
+            graph=self._build_pgnode(
+                process_id="aggregate_spatial",
+                data=THIS,
+                geometries=geometries,
+                reducer=reducer,
+                arguments=dict_no_none(
+                    target_dimension=target_dimension, context=context
+                ),
+            ),
+            connection=self._connection,
+            # TODO: metadata?
         )
 
     @staticmethod
@@ -1970,7 +1985,7 @@ def save_user_defined_process(
             returns=returns, categories=categories, examples=examples, links=links,
         )
 
-    def execute(self) -> Dict:
+    def execute(self) -> dict:
         """Executes the process graph of the imagery. """
         return self._connection.execute(self.flat_graph())
 
diff --git a/openeo/rest/vectorcube.py b/openeo/rest/vectorcube.py
index 9b7c195e3..275381d0c 100644
--- a/openeo/rest/vectorcube.py
+++ b/openeo/rest/vectorcube.py
@@ -70,7 +70,12 @@ def save_result(self, format: str = "GeoJson", options: dict = None):
             }
         )
 
+    def execute(self) -> dict:
+        """Executes the process graph of the imagery."""
+        return self._connection.execute(self.flat_graph())
+
     def download(self, outputfile: str, format: str = "GeoJSON", options: dict = None):
+        # TODO: only add save_result, when not already present (see DataCube.download)
         cube = self.save_result(format=format, options=options)
         return self._connection.download(cube.flat_graph(), outputfile)